Mechanical BEAMST User`s Manual

Mechanical BEAMST User`s Manual
Mechanical BEAMST User's Manual
ANSYS, Inc.
Southpointe
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Canonsburg, PA 15317
[email protected]
http://www.ansys.com
(T) 724-746-3304
(F) 724-514-9494
Release 15.0
November 2013
ANSYS, Inc. is
certified to ISO
9001:2008.
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Table of Contents
1. BEAMST Introduction ............................................................................................................................. 1
2. Facilities in BEAMST ................................................................................................................................ 3
2.1. Selection of Members and Joints ....................................................................................................... 3
2.2. Section Properties for BEAMST .......................................................................................................... 3
2.3. Beam Local Axes Considerations ....................................................................................................... 4
2.4. Section Orientation .......................................................................................................................... 4
2.5. Member Stress Evaluation ................................................................................................................. 5
2.6. Loadcase Combinations and Classification ........................................................................................ 5
2.7. Code Checking in BEAMST ................................................................................................................ 6
2.8. Obtaining Results ............................................................................................................................. 6
2.8.1. Accessing Results using Excel ................................................................................................... 6
2.8.1.1. Compatibility .................................................................................................................. 7
2.8.1.2. Installing the Excel Plugin ................................................................................................ 7
2.8.1.3. Available Function Descriptions ....................................................................................... 8
2.8.1.3.1. Functions to Retrieve Basic Model Information ........................................................ 9
2.8.1.3.2. Results Database Functions ................................................................................... 13
2.8.1.3.3. Miscellaneous Functions ....................................................................................... 15
2.8.2. Accessing Results using Python .............................................................................................. 16
2.8.3. BEAMST Results ...................................................................................................................... 18
2.8.3.1. Member Properties ........................................................................................................ 19
2.8.3.2. Member Forces .............................................................................................................. 20
2.8.3.3. Member Stresses ........................................................................................................... 21
2.8.3.4. AISC WSD and LRFD Member Unity Checks .................................................................... 21
2.8.3.4.1. AISC WSD Checks .................................................................................................. 22
2.8.3.4.2. AISC LRFD Checks ................................................................................................. 22
2.8.3.5. API WSD and LRFD Member Unity Checks ...................................................................... 23
2.8.3.5.1. API WSD Checks .................................................................................................... 23
2.8.3.5.2. API WSD Checks (Spectral) ..................................................................................... 24
2.8.3.5.3. API LRFD Checks ................................................................................................... 25
2.8.3.6. API WSD and LRFD HYDR Checks .................................................................................... 26
2.8.3.6.1. WSD Checks .......................................................................................................... 26
2.8.3.6.2. LRFD Checks ......................................................................................................... 27
2.8.3.7. API WSD NOMI/JOIN Checks .......................................................................................... 28
2.8.3.7.1. Edition 16 to Edition 20 ......................................................................................... 28
2.8.3.7.2. Edition 21 Onwards ............................................................................................... 29
2.8.3.8. API WSD and LRFD PUNC Checks ................................................................................... 31
2.8.3.8.1. WSD Checks .......................................................................................................... 31
2.8.3.8.2. LRFD Checks ......................................................................................................... 32
2.8.3.9. API LRFD Joint Checks .................................................................................................... 33
2.8.3.10. BS5950 Member Checks ............................................................................................... 35
2.8.3.11. DS449 Member Checks ................................................................................................ 36
2.8.3.12. DS449 Joint Checks ...................................................................................................... 37
2.8.3.13. NPD Member Checks ................................................................................................... 39
2.8.3.14. NPD Joint Checks ......................................................................................................... 41
2.8.3.15. NORSOK Member Checks ............................................................................................. 43
2.8.3.16. NORSOK HYDR Checks ................................................................................................. 44
2.8.3.17. NORSOK Joint Checks .................................................................................................. 44
2.8.3.18. ISO Member Checks ..................................................................................................... 46
2.8.3.19. ISO HYDR Checks ......................................................................................................... 47
2.8.3.20. ISO Joint Checks .......................................................................................................... 47
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BEAMST User's Manual
3. BEAMST Command Reference .............................................................................................................. 51
3.1. BEAMST Command Structures ......................................................................................................... 51
3.1.1. BEAMST Command Syntax ..................................................................................................... 51
3.1.2. BEAMST Command Data Types ............................................................................................... 52
3.1.3. BEAMST Command Special Symbols ....................................................................................... 53
3.1.4. BEAMST NOT Command Modifier ........................................................................................... 54
3.2. BEAMST Command Sets .................................................................................................................. 54
3.3. BEAMST Priority of Data Assignments .............................................................................................. 56
3.4. ABNO ............................................................................................................................................. 57
3.5. AISC ............................................................................................................................................... 58
3.6. ANSYS ............................................................................................................................................ 59
3.7. API ................................................................................................................................................. 61
3.8. BRIG ............................................................................................................................................... 62
3.9. BS59 ............................................................................................................................................... 63
3.10. CASE ............................................................................................................................................. 63
3.11. CB ................................................................................................................................................ 64
3.12. CHOR ............................................................................................................................................ 65
3.13. CMBV ........................................................................................................................................... 66
3.14. CMY/CMZ ..................................................................................................................................... 67
3.15. COMB ........................................................................................................................................... 68
3.16. COMPONENT ................................................................................................................................ 69
3.17. COOR ........................................................................................................................................... 70
3.18. DENT ............................................................................................................................................ 71
3.19. DESI .............................................................................................................................................. 72
3.20. DS449 ........................................................................................................................................... 74
3.21. EFFE ............................................................................................................................................. 75
3.22. ELEM ............................................................................................................................................ 76
3.23. ELEV ............................................................................................................................................. 77
3.24. END .............................................................................................................................................. 78
3.25. EXTR ............................................................................................................................................. 78
3.26. FILES ............................................................................................................................................. 79
3.27. FORC ............................................................................................................................................ 79
3.28. GAPD ............................................................................................................................................ 80
3.29. GRAV ............................................................................................................................................ 81
3.30. GROU ........................................................................................................................................... 82
3.31. HYDR ............................................................................................................................................ 82
3.32. ISO ............................................................................................................................................... 83
3.33. JOB ............................................................................................................................................... 84
3.34. JOIN ............................................................................................................................................. 84
3.35. LIBR .............................................................................................................................................. 85
3.36. LIMIT ............................................................................................................................................ 86
3.37. MATE ............................................................................................................................................ 86
3.38. MCOF ........................................................................................................................................... 87
3.39. MFAC ............................................................................................................................................ 89
3.40. MLTF ............................................................................................................................................. 90
3.41. MOVE ........................................................................................................................................... 90
3.42. NORS ............................................................................................................................................ 91
3.43. NPD .............................................................................................................................................. 92
3.44. OPTI ............................................................................................................................................. 93
3.45. PHI ............................................................................................................................................... 94
3.46. POST ............................................................................................................................................ 95
3.47. PRIN ............................................................................................................................................. 95
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3.48. PROF .......................................................................................................................................... 103
3.49. PROJECT ..................................................................................................................................... 105
3.50. QUAK .......................................................................................................................................... 106
3.51. RENU .......................................................................................................................................... 106
3.52. RESU ........................................................................................................................................... 107
3.53. SAFE ........................................................................................................................................... 107
3.54. SAVE ........................................................................................................................................... 108
3.55. SEAR ........................................................................................................................................... 110
3.56. SECO .......................................................................................................................................... 111
3.57. SECT ........................................................................................................................................... 111
3.58. SELE ........................................................................................................................................... 112
3.59. SIMP ........................................................................................................................................... 113
3.60. SPEC ........................................................................................................................................... 114
3.61. STRU ........................................................................................................................................... 115
3.62. STUB ........................................................................................................................................... 115
3.63. SYST ........................................................................................................................................... 116
3.64. TEXT ........................................................................................................................................... 117
3.65. TITLE ........................................................................................................................................... 117
3.66. TOPO .......................................................................................................................................... 118
3.67. TYPE ........................................................................................................................................... 119
3.68. ULCF ........................................................................................................................................... 121
3.69. UNBR .......................................................................................................................................... 123
3.70. UNIT ........................................................................................................................................... 124
3.71. WAVE .......................................................................................................................................... 125
3.72. YIEL ............................................................................................................................................ 126
4. BEAMST AISC Theory ........................................................................................................................... 129
4.1. AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO) .............................. 129
4.1.1. AISC WSD ALLO Overview ..................................................................................................... 129
4.1.2. AISC WSD ALLO Unity Check Report ...................................................................................... 132
4.1.3. AISC WSD ALLO Nomenclature ............................................................................................. 135
4.1.3.1. AISC WSD ALLO Nomenclature - Dimensional ............................................................... 135
4.1.3.2. AISC WSD ALLO Nomenclature - Acting Stresses ........................................................... 137
4.1.3.3. AISC WSD ALLO Nomenclature - Allowable Stresses ...................................................... 137
4.1.4. AISC WSD Allowable Stresses and Unity Checks ..................................................................... 138
4.1.4.1. AISC WSD Allowable Stress Increase ............................................................................. 138
4.1.4.2. AISC WSD ALLO - Axial Tension Checks ......................................................................... 138
4.1.4.3. AISC WSD ALLO - Axial Compression Checks ................................................................. 139
4.1.4.4. AISC WSD ALLO - Bending Checks ................................................................................ 141
4.1.4.5. AISC WSD ALLO - Shear Checks .................................................................................... 146
4.1.4.6. AISC WSD ALLO - Unity Checks ..................................................................................... 148
4.1.4.7. AISC WSD ALLO - Combined Stress Unity Checks .......................................................... 149
4.1.4.8. AISC WSD ALLO - Combined Axial and Bending Unity Check ......................................... 150
4.1.4.9. AISC WSD ALLO - Bending Coefficient, Cb ...................................................................... 151
4.1.4.10. AISC WSD ALLO - Amplification Reduction Factors, Cmy, Cmz ........................................ 152
4.1.5. Spectral Loadcases and ‘Automatic Signed Expansion Procedures’ ......................................... 153
4.1.5.1. Torsional Effects ........................................................................................................... 154
4.1.5.2. Axial Unity Check and the Axial Component of Combined Stress Buckle and Yield Unity
Checks .................................................................................................................................... 154
4.1.5.3. Local Axes Shear Unity Checks and Maximum Shear Unity Check for Tubular Sections .... 154
4.1.5.4. Local Axes Pure Bending Unity Checks and Bending Components of Combined Stresses
Yield Unity Check .................................................................................................................... 155
4.1.5.5. Unity Check Report for Shear, Pure Bending and Yield Unity Checks .............................. 155
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4.1.5.6. AISC Combined Stress Buckle Unity Check .................................................................... 156
4.2. AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB) ................................... 157
4.2.1. AISC LRFD MEMB Overview .................................................................................................. 157
4.2.2. AISC LRFD Unity Check Report .............................................................................................. 160
4.2.3. AISC LRFD MEMB Nomenclature ........................................................................................... 163
4.2.3.1. AISC LRFD MEMB Nomenclature - Definition of Symbols ............................................... 163
4.2.3.2. AISC LRFD MEMB Nomenclature - Dimensional ............................................................ 163
4.2.3.3. AISC LRFD MEMB Nomenclature - Acting Forces and Stresses ....................................... 165
4.2.3.4. AISC LRFD MEMB Nomenclature - Strengths and Utilizations ........................................ 165
4.2.3.5. AISC LRFD MEMB Nomenclature - Parameters ............................................................... 166
4.2.4. AISC LRFD MEMBER CHECKS ................................................................................................. 166
4.2.4.1. AISC LRFD - Partial Coefficients .................................................................................... 166
4.2.4.2. AISC LRFD - Nominal Axial Tension Strength ................................................................. 167
4.2.4.3. AISC LRFD - Nominal Axial Compressive Strength ......................................................... 167
4.2.4.4. AISC LRFD - Bending Strength ...................................................................................... 171
4.2.4.5. AISC LRFD - Major Axis Bending Strength ..................................................................... 171
4.2.4.6. AISC LRFD - Slender web .............................................................................................. 174
4.2.4.7. AISC LRFD - Minor Axis Bending Strength ..................................................................... 175
4.2.4.8. AISC LRFD - Bending Strength Box and RHS .................................................................. 176
4.2.4.9. AISC LRFD - Bending Strength Tubes ............................................................................ 178
4.2.4.10. AISC LRFD MEMB - Shear ............................................................................................ 179
4.2.4.11. AISC LRFD MEMB - Unity Checks ................................................................................. 181
4.2.4.12. AISC LRFD MEMB - Combined Stress Unity Checks ...................................................... 182
4.2.4.13. AISC LRFD MEMB - Bending Coefficient, Cb ................................................................. 183
4.2.4.14. AISC LRFD MEMB - Amplification Reduction Factors, Cmy, Cmz ...................................... 184
4.2.5. AISC LRFD MEMBER CHECKS - 3rd Edition ............................................................................. 185
4.2.5.1. AISC LRFD - 3rd Edition - Partial Coefficients ................................................................. 186
4.2.5.2. AISC LRFD - 3rd Edition - Nominal Axial Tension Strength .............................................. 186
4.2.5.3. AISC LRFD - 3rd Edition - Nominal Axial Compressive Strength ...................................... 186
4.2.5.4. AISC LRFD - 3rd Edition - Bending Strength .................................................................. 190
4.2.5.5. AISC LRFD - 3rd Edition - Major Axis Bending Strength .................................................. 190
4.2.5.6. AISC LRFD - 3rd Edition - Slender web .......................................................................... 193
4.2.5.7. AISC LRFD - 3rd Edition - Minor Axis Bending Strength ................................................. 194
4.2.5.8. AISC LRFD - 3rd Edition - Bending Strength Box and RHS .............................................. 195
4.2.5.9. AISC LRFD - 3rd Edition - Bending Strength Tubes ......................................................... 197
4.2.5.10. AISC LRFD MEMB - Shear ............................................................................................ 198
4.2.5.11. AISC LRFD MEMB - Unity Checks ................................................................................. 200
4.2.5.12. AISC LRFD MEMB - Combined Stress Unity Checks ...................................................... 201
4.2.5.13. AISC LRFD MEMB - Bending Coefficient, Cb ................................................................. 202
4.2.5.14. AISC LRFD MEMB - Amplification Reduction Factors, Cmy, Cmz ...................................... 203
5. BEAMST API Theory ............................................................................................................................. 205
5.1. API Working Stress Design Allowable Member Stress Check (API WSD ALLO) .................................. 205
5.1.1. API WSD ALLO Overview ....................................................................................................... 205
5.1.2. API WSD ALLO Unity Check Report ........................................................................................ 208
5.1.3. API WSD ALLO Nomenclature ............................................................................................... 210
5.1.3.1. API WSD ALLO Nomenclature - Dimensional ................................................................. 210
5.1.3.2. API WSD ALLO Nomenclature - Acting Section Forces and Stresses ............................... 211
5.1.3.3. API WSD ALLO Nomenclature - Allowable Stresses and Unity Checks ............................. 211
5.1.3.4. API WSD ALLO Nomenclature - Parameters ................................................................... 212
5.1.4. API WSD ALLO Stresses and Unity Checks .............................................................................. 213
5.1.4.1. API WSD ALLO Stress Increase ...................................................................................... 213
5.1.4.2. API WSD ALLO - Tension ............................................................................................... 213
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5.1.4.3. API WSD ALLO - Compression ....................................................................................... 214
5.1.4.4. API WSD ALLO - Bending .............................................................................................. 214
5.1.4.5. API WSD ALLO - Shear .................................................................................................. 215
5.1.4.6. API WSD ALLO - Unity Checks ....................................................................................... 215
5.1.4.7. API WSD ALLO - Combined Stresses .............................................................................. 216
5.1.5. Spectral Loadcases ............................................................................................................... 217
5.1.5.1. Torsional Effects ........................................................................................................... 217
5.1.5.2. Axial Unity Check and the Axial Component of Combined Stress Buckle and Yield Unity
Checks .................................................................................................................................... 217
5.1.5.3. Local Axes Shear Unity Checks and Maximum Shear Unity Check for Tubular Sections .... 218
5.1.5.4. Local Axes Pure Bending Unity Checks and Bending Components of Combined Stresses
Yield Unity Check .................................................................................................................... 218
5.1.5.5. Unity Check Report for Shear, Pure Bending and Yield Unity Checks .............................. 219
5.1.5.6. API Combined Stress Buckle Unity Check ...................................................................... 219
5.2. API Hydrostatic Collapse Check (API WSD HYDR) ............................................................................ 220
5.2.1. API WSD HYDR Overview ...................................................................................................... 221
5.2.2. API Hydrostatic Unity Check Report ...................................................................................... 224
5.2.3. API WSD HYDR Nomenclature ............................................................................................... 224
5.2.3.1. API WSD HYDR Nomenclature - Dimensional ................................................................ 225
5.2.3.2. API WSD HYDR Nomenclature - Acting Section Forces and Stresses ............................... 225
5.2.3.3. API WSD HYDR Nomenclature - Allowable Stresses and Unity Checks ............................ 225
5.2.4. API Allowable Stresses and Unity Checks ............................................................................... 226
5.2.4.1. API Allowable - Limit Checks ........................................................................................ 228
5.2.4.2. API Allowable - Elastic Hoop Buckling Stress Fhe ........................................................... 229
5.2.4.3. API Allowable - Critical Hoop Buckling Stress Fhc ........................................................... 229
5.2.4.4. API WSD - Allowable Critical Hoop Buckling Stress Fch ................................................... 230
5.2.4.5. API WSD - Critical Axial Elastic Local Buckling Stress Fxe ................................................. 230
5.2.4.6. API WSD - Allowable Axial Elastic Local Buckling Stress Faa ............................................ 230
5.2.4.7. API WSD - Inelastic Axial Elastic Local Buckling Stress Fxc ............................................... 230
5.2.4.8. API WSD - Hoop Compressive Unity Check UCH ............................................................ 230
5.2.4.9. API WSD - Axial Tension Unity Check UCT ...................................................................... 231
5.2.4.10. API WSD - Combined Compression and Hydrostatic Pressure Unity Check UCCH1/2 ....... 231
5.2.4.11. API WSD - Combined Tension and Hydrostatic Pressure Unity Check UCTH ................... 231
5.3. API Joint Strength Check (API WSD JOIN) ....................................................................................... 231
5.3.1. API WSD JOIN Overview ....................................................................................................... 232
5.3.2. API WSD JOIN Check Report .................................................................................................. 235
5.3.3. API WSD JOIN Nomenclature ................................................................................................ 236
5.3.3.1. API WSD JOIN Nomenclature - Dimensional .................................................................. 236
5.3.3.2. API WSD JOIN Nomenclature - Acting Forces and Stresses ............................................. 237
5.3.3.3. API WSD JOIN Nomenclature - Allowable Stresses and Unity Checks .............................. 237
5.3.4. API WSD JOIN Allowable Loads and Unity Checks .................................................................. 238
5.3.4.1. API WSD JOIN Allowable - Basic Capacity ...................................................................... 238
5.3.4.2. API WSD JOIN Allowable - Strength Factor Qu ............................................................... 239
5.3.4.3. API WSD JOIN Allowable - Strength Factor Qf ................................................................ 239
5.3.4.4. API WSD JOIN - Joints with Thickened Cans .................................................................. 240
5.3.4.5. API WSD JOIN - Nominal Load Unit Checks ................................................................... 240
5.3.4.6. API WSD JOIN - Combined Axial and Bending Unity Checks .......................................... 240
5.3.5. Spectral Expansion for Joint Checks (API WSD JOIN) .............................................................. 240
5.4. API Punching Shear Joint Check (API WSD PUNC) ........................................................................... 241
5.4.1. API WSD PUNC Overview ...................................................................................................... 241
5.4.2. API Punching Shear Check Report ......................................................................................... 245
5.4.3. API WSD PUNC Nomenclature ............................................................................................... 245
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5.4.3.1. API WSD PUNC Nomenclature - Dimensional ................................................................ 246
5.4.3.2. API WSD PUNC Nomenclature - Acting Section Forces and Stresses ............................... 246
5.4.3.3. API WSD PUNC Nomenclature - Allowable Stresses and Unity Checks ............................ 247
5.4.4. API Allowable Punching Shear Stresses and Unity Checks ...................................................... 247
5.4.4.1. API Allowable - Acting Punching Shear Vp .................................................................... 248
5.4.4.2. API Allowable - Chord Design Factor Qf ........................................................................ 248
5.4.4.3. API Allowable - Geometry and Load Factor Qq .............................................................. 248
5.4.4.4. API WSD - Allowable Punching Shear Vp ....................................................................... 249
5.4.4.5. API WSD - Punching Shear Unity Checks ....................................................................... 250
5.4.4.6. API WSD - Combined Axial and Bending Stress Unity Checks ......................................... 250
5.4.4.7. API WSD - Joint Strength Unity Check ........................................................................... 251
5.4.5. Spectral Expansion for Joint Checks (API PUNC) ..................................................................... 251
5.5. API Nominal Load Check (API WSD NOMI) ...................................................................................... 252
5.5.1. API WSD NOMI Overview ...................................................................................................... 252
5.5.2. API Nominal Load Check Report ........................................................................................... 255
5.5.3. API WSD NOMI Nomenclature ............................................................................................... 256
5.5.3.1. API WSD NOMI Nomenclature - Dimensional ................................................................ 257
5.5.3.2. API WSD NOMI Nomenclature - Acting Forces and Stresses ........................................... 257
5.5.3.3. API WSD NOMI Nomenclature - Allowable Stresses and Unity Checks ............................ 258
5.5.4. API Allowable Nominal Loads and Unity Checks .................................................................... 259
5.5.4.1. API Allowable - Chord Design Factor Qf ........................................................................ 259
5.5.4.2. API Allowable - Ultimate Strength Factor Qu ................................................................. 259
5.5.4.3. API Allowable - Allowable Nominal Loads ..................................................................... 260
5.5.4.4. API WSD - Nominal Load Unity Checks .......................................................................... 261
5.5.4.5. API WSD - Combined Axial and Bending Unity Checks .................................................. 261
5.5.4.6. API WSD - Interpolated Joints ....................................................................................... 261
5.5.4.7. API WSD - Joint Strength Unity Check ........................................................................... 262
5.5.5. Spectral Expansion for Joint Checks (API NOMI) ..................................................................... 262
5.6. API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD MEMB) ............. 263
5.6.1. API LRFD MEMB Overview .................................................................................................... 263
5.6.2. API LRFD MEMB Unity Check Report ..................................................................................... 266
5.6.3. API LRFD MEMB Nomenclature ............................................................................................. 268
5.6.3.1. API LRFD MEMB Nomenclature - Dimensional .............................................................. 268
5.6.3.2. API LRFD MEMB Nomenclature - Acting Section Stresses .............................................. 269
5.6.3.3. API LRFD MEMB Nomenclature - Allowable Stresses and Unity Checks .......................... 269
5.6.3.4. API LRFD MEMB Nomenclature - Parameters ................................................................. 271
5.6.4. API LRFD Allowable Stresses and Unity Checks ...................................................................... 271
5.6.4.1. API LRFD Partial Coefficients ........................................................................................ 271
5.6.4.2. API LRFD - Allowable Tension Stress, Ft .......................................................................... 272
5.6.4.3. API LRFD - Allowable Compression Stress, Fa ................................................................. 272
5.6.4.4. API LRFD - Allowable Bending Stress, Fb ........................................................................ 273
5.6.4.5. API LRFD Allowable Shear Stress, Fv and Fvt ................................................................... 274
5.6.4.6. API LRFD MEMB - Unity Checks .................................................................................... 274
5.6.4.7. API LRFD MEMB - Combined Stresses ........................................................................... 275
5.6.5. Spectral Loadcases ............................................................................................................... 276
5.6.5.1. Torsional Effects ........................................................................................................... 276
5.6.5.2. Axial Unity Check and the Axial Component of Combined Stress Buckle and Yield Unity
Checks .................................................................................................................................... 276
5.6.5.3. Local Axes Shear Unity Checks and Maximum Shear Unity Check for Tubular Sections .... 277
5.6.5.4. Local Axes Pure Bending Unity Checks and Bending Components of Combined Stresses
Yield and Buckle Unity Checks ................................................................................................. 277
5.6.5.5. Unity Check Report for Spectral Cases .......................................................................... 277
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5.6.5.6. API Combined Stress Buckle Unity Check (Buckle CSR) .................................................. 278
5.7. API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR) ...................... 278
5.7.1. API LRFD HYDR Overview ..................................................................................................... 278
5.7.2. API LRFD Hydrostatic Unity Check Report .............................................................................. 281
5.7.3. API LRFD HYDR Nomenclature .............................................................................................. 282
5.7.3.1. API LRFD HYDR Nomenclature - Dimensional ............................................................... 282
5.7.3.2. API LRFD HYDR Nomenclature - Acting Section Forces and Stresses .............................. 283
5.7.3.3. API LRFD HYDR Nomenclature - Allowable Stresses and Unity Checks ........................... 283
5.7.3.4. API LRFD HYDR Nomenclature - Parameters ................................................................. 285
5.7.4. API LRFD - Allowable Stresses and Unity Checks .................................................................... 285
5.7.4.1. API LRFD HYDR - Design Hydrostatic Pressure ............................................................... 286
5.7.4.2. API LRFD HYDR - Limit Checks ...................................................................................... 286
5.7.4.3. API LRFD HYDR - Elastic Hoop Buckling Stress Fhe ......................................................... 287
5.7.4.4. API LRFD HYDR - Allowable Elastic Hoop Buckling Stress Fha ......................................... 287
5.7.4.5. API LRFD HYDR - Critical Hoop Buckling Stress Fhc ........................................................ 287
5.7.4.6. API LRFD HYDR - Allowable Critical Hoop Buckling Stress Fch ........................................ 288
5.7.4.7. API LRFD HYDR - Critical Axial Elastic Local Buckling Stress Fxe ...................................... 288
5.7.4.8. API LRFD HYDR - Allowable Axial Elastic Local Buckling Stress Fxa .................................. 288
5.7.4.9. API LRFD HYDR - Inelastic Axial Local Buckling Stress Fxc ............................................... 288
5.7.4.10. API LRFD HYDR - Allowable Inelastic Axial Local Buckling Stress Fca ............................. 289
5.7.4.11. API LRFD HYDR - Hoop Compressive Unity Check UCH ................................................ 289
5.7.4.12. API LRFD HYDR - Allowable Tension Stress Ft ............................................................... 289
5.7.4.13. API LRFD HYDR - Allowable Axial Compression Stress Fa .............................................. 289
5.7.4.14. API LRFD HYDR - Allowable Bending Stress Fb ............................................................. 290
5.7.4.15. API LRFD HYDR - Axial Tension Check UCax ................................................................. 290
5.7.4.16. API LRFD HYDR - Combined Tension and Hydrostatic Pressure Unity Check UCc ........... 291
5.7.4.17. API LRFD HYDR - Combined Compression and Hydrostatic Pressure Unity Checks ....... 291
5.8. API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN) ................................. 292
5.8.1. API LRFD JOIN Overview ....................................................................................................... 292
5.8.2. API LRFD JOIN Check Report ................................................................................................. 296
5.8.3. API LRFD JOIN Nomenclature ................................................................................................ 296
5.8.3.1. API LRFD JOIN Nomenclature - Dimensional ................................................................. 297
5.8.3.2. API LRFD JOIN Nomenclature - Acting Forces and Stresses ............................................ 298
5.8.3.3. API LRFD JOIN Nomenclature - Allowable Stresses and Unity Checks ............................. 298
5.8.3.4. API LRFD JOIN Nomenclature - Parameters ................................................................... 299
5.8.4. API Allowable Nominal Loads and Unity Checks .................................................................... 299
5.8.4.1. API LRFD JOIN - Chord Design Factor Qf ........................................................................ 300
5.8.4.2. API LRFD JOIN - Ultimate Strength Factor Qu ................................................................ 300
5.8.4.3. API LRFD JOIN - Allowable Nominal Loads .................................................................... 301
5.8.4.4. API LRFD JOIN - Load Transfer Across Chords ................................................................ 301
5.8.4.5. API LRFD JOIN - Nominal Load Unity Checks ................................................................. 302
5.8.4.6. API LRFD JOIN - Combined Axial and Bending Unity Checks UCco .................................. 302
5.8.4.7. API LRFD JOIN - Interpolated Joints .............................................................................. 302
5.8.4.8. API LRFD JOIN - Load Transfer Check UCx ...................................................................... 302
5.8.4.9. API LRFD JOIN - Joint Strength Unity Check UCjy ........................................................... 303
5.8.5. Spectral Expansion for Joint Checks (API LRFD) ..................................................................... 303
6. BEAMST BS59 Theory .......................................................................................................................... 305
6.1. BS5950 Allowable Member Check (BS59 MEMB) ............................................................................ 305
6.1.1. BS59 MEMB Overview .......................................................................................................... 305
6.1.2. BS59 Allowable Unity Check Report ...................................................................................... 308
6.1.3. BS59 MEMB Nomenclature ................................................................................................... 309
6.1.3.1. BS59 MEMB Nomenclature - Dimensional ..................................................................... 309
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6.1.3.2. BS59 MEMB Nomenclature - Acting Forces and Stresses ................................................ 311
6.1.3.3. BS59 MEMB Nomenclature - Allowable Stresses and Unity Checks ................................. 311
6.1.4. BS5950 Local Cross Section Checks ....................................................................................... 312
6.1.4.1. BS59 MEMB - Section Classification .............................................................................. 313
6.1.4.2. BS59 MEMB - Axial Tension Unity Check ........................................................................ 317
6.1.4.3. BS59 MEMB - Major Axis Shear Unity Check .................................................................. 317
6.1.4.4. BS59 MEMB - Minor Axis Shear Unity Check .................................................................. 317
6.1.4.5. BS59 MEMB - Major Axis Shear Unity Checks, Low Shear Load ....................................... 318
6.1.4.6. BS59 MEMB - Major Axis Shear Unity Checks, High Shear Load ...................................... 319
6.1.4.7. BS59 MEMB - Minor Axis Shear Unity Checks, Low Shear Load ....................................... 323
6.1.4.8. BS59 MEMB - Minor Axis Shear Unity Checks, High Shear Load ...................................... 324
6.1.4.9. BS59 MEMB - Axial Force plus Moment Unity Check ...................................................... 327
6.1.4.10. BS59 MEMB - Simplified Axial Force and Moment ....................................................... 334
6.1.5. BS5950 Overall Member Checks ............................................................................................ 335
6.1.5.1. BS59 MEMB - Major Axis Compressive Buckling ............................................................ 335
6.1.5.2. BS59 MEMB - Minor Axis Compressive Buckling ............................................................ 338
6.1.5.3. BS59 MEMB - Lateral Torsional Buckling ........................................................................ 339
6.1.5.4. BS59 MEMB - Overall Buckling ...................................................................................... 343
6.1.5.5. BS59 MEMB - Overall Buckling - Simplified Method ....................................................... 344
6.1.6. BS59 MEMB - Thin or Slender Webs ....................................................................................... 344
7. BEAMST DS44 Theory .......................................................................................................................... 347
7.1. DS449 Member Checks (DS44 MEMB) ............................................................................................ 347
7.1.1. DS44 MEMB Overview .......................................................................................................... 347
7.1.2. DS449 MEMB Unity Check Report ......................................................................................... 350
7.1.3. DS449 MEMB Nomenclature ................................................................................................. 351
7.1.3.1. DS449 MEMB Nomenclature - Dimensional .................................................................. 351
7.1.3.2. DS449 MEMB Nomenclature - Acting Forces and Stresses ............................................. 352
7.1.3.3. DS449 MEMB Nomenclature - Allowable Stresses and Unity Checks .............................. 352
7.1.4. DS449 Member Unity Check Calculations .............................................................................. 353
7.1.4.1. DS449 MEMB - Partial Material Coefficients ................................................................... 353
7.1.4.2. DS449 MEMB - von Mises Stress ................................................................................... 353
7.1.4.3. DS449 MEMB - Total Buckling ....................................................................................... 354
7.1.4.4. DS449 MEMB - Local Buckling Axial and Bending Stresses ............................................. 356
7.1.4.5. DS449 MEMB - Local Buckling Hydrostatic Overpressure ............................................... 357
7.1.4.6. DS449 MEMB - Local Buckling Combined Actions ......................................................... 359
7.1.4.7. DS449 MEMB - Unity Check Values ............................................................................... 359
7.2. DS449 Joint Checks (DS44 JOIN) .................................................................................................... 360
7.2.1. DS44 JOIN Overview ............................................................................................................. 360
7.2.2. NPD JOIN Unity Check Report ............................................................................................... 363
7.2.3. DS449 JOIN Nomenclature ................................................................................................... 363
7.2.3.1. DS449 JOIN Nomenclature - Dimensional ..................................................................... 364
7.2.3.2. DS449 JOIN Nomenclature - Acting Forces and Stresses ................................................ 364
7.2.3.3. DS449 JOIN Nomenclature - Allowable Stresses and Unity Checks ................................. 365
7.2.3.4. DS449 JOIN Nomenclature - Parameters ....................................................................... 365
7.2.4. DS449 Joint Checks .............................................................................................................. 366
7.2.4.1. DS449 JOIN - Partial Material Coefficients ..................................................................... 366
7.2.4.2. DS449 JOIN - Critical Load Capacity .............................................................................. 366
7.2.4.3. DS449 JOIN - Joint Capacity ......................................................................................... 368
7.2.4.4. DS449 JOIN - Unity Checks ........................................................................................... 368
8. BEAMST NPD Theory ........................................................................................................................... 369
8.1. NPD and NS3472 Member Checks (NPD MEMB) ............................................................................. 369
8.1.1. NPD MEMB Overview ........................................................................................................... 369
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8.1.2. NPD MEMB Unity Check Report ............................................................................................ 373
8.1.3. NPD MEMB Nomenclature .................................................................................................... 373
8.1.3.1. NPD MEMB Nomenclature - Dimensional ..................................................................... 373
8.1.3.2. NPD MEMB Nomenclature - Acting Forces and Stresses ................................................ 375
8.1.3.3. NPD MEMB Nomenclature - Allowable Stresses and Unity Checks ................................. 375
8.1.3.4. NPD MEMB Nomenclature - Parameters ........................................................................ 376
8.1.4. NPD MEMB - Methods of von Mises stress calculation for NPD code checks ............................ 377
8.1.5. NPD MEMB - NPD and NS3472 Ultimate Limit State Compliance Checks ................................ 380
8.1.6. NPD 1992 Member Checks - Tubular Members ...................................................................... 381
8.1.6.1. NPD MEMB - Material and Structural Coefficients .......................................................... 381
8.1.6.2. NPD MEMB - von Mises Unity Check ............................................................................. 381
8.1.6.3. NPD MEMB - Elastic Buckling Resistance for Unstiffened Cylindrical Shells ..................... 382
8.1.6.4. NPD MEMB - Global Buckling Check ............................................................................. 383
8.1.7. NPD Member Checks - Non-Tubular Members ....................................................................... 385
8.1.7.1. NPD MEMB - Material and Structural Coefficients .......................................................... 385
8.1.7.2. NPD MEMB - Global Buckling ....................................................................................... 386
8.1.7.3. NPD MEMB - Torsional Buckling .................................................................................... 388
8.1.7.4. NPD MEMB - Lateral Buckling ....................................................................................... 389
8.1.7.5. NPD MEMB - Unity Check Values .................................................................................. 390
8.2. NPD Joint Checks (NPD JOIN) ........................................................................................................ 391
8.2.1. NPD JOIN Overview .............................................................................................................. 391
8.2.2. NPD JOIN Unity Check Report ............................................................................................... 394
8.2.3. NPD JOIN Nomenclature ...................................................................................................... 394
8.2.3.1. NPD JOIN Nomenclature - Dimensional ........................................................................ 395
8.2.3.2. NPD JOIN Nomenclature - Acting Forces and Stresses ................................................... 395
8.2.3.3. NPD JOIN Nomenclature - Allowable Stresses, Capacities and Unity Checks ................... 396
8.2.3.4. NPD JOIN Nomenclature - Parameters .......................................................................... 396
8.2.4. NPD 1992 Joint Checks ......................................................................................................... 396
8.2.4.1. NPD JOIN - Nominal Longitudinal Chord Stress ............................................................. 397
8.2.4.2. NPD JOIN - Characteristic Capacities ............................................................................. 397
8.2.4.3. NPD JOIN - Unity Checks .............................................................................................. 398
9. BEAMST NORSOK Theory .................................................................................................................... 399
9.1. NORSOK Member Code Check (NORS MEMB) ................................................................................. 399
9.1.1. NORS MEMB Overview ......................................................................................................... 399
9.1.2. NORSOK MEMB Unity Check Report ...................................................................................... 402
9.1.3. NORS MEMB Nomenclature .................................................................................................. 402
9.1.3.1. NORS MEMB Nomenclature - Dimensional .................................................................... 402
9.1.3.2. NORS MEMB Nomenclature - Acting Section Stresses ................................................... 403
9.1.3.3. NORS MEMB Nomenclature - Design Strengths and Unity Checks ................................. 403
9.1.3.4. NORS MEMB Nomenclature - Parameters ...................................................................... 405
9.1.4. NORSOK Design Strengths and Unity Checks ........................................................................ 405
9.1.4.1. Design Tension Strength, Nt ......................................................................................... 406
9.1.4.2. Design Compression Strength, Na ................................................................................. 406
9.1.4.3. Design Bending Strength, MR ....................................................................................... 407
9.1.4.4. Design Shear Strengths, VR and MTR .............................................................................. 407
9.1.4.5. Material Factor, γm ....................................................................................................... 408
9.1.4.6. NORS MEMB - Unity Checks .......................................................................................... 409
9.1.4.7. NORS MEMB - Combined Forces ................................................................................... 409
9.2. NORSOK Hydrostatic Member Collapse Checks (NORS HYDR) ......................................................... 411
9.2.1. NORS HYDR Overview .......................................................................................................... 411
9.2.2. NORSOK Hydrostatic Collapse Member Unity Check Report ................................................... 412
9.2.3. NORS HYDR Nomenclature ................................................................................................... 415
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9.2.3.1. NORS HYDR Nomenclature - Dimensional .................................................................... 415
9.2.3.2. NORS HYDR Nomenclature - Acting Section Forces and Stresses ................................... 416
9.2.3.3. NORS HYDR Nomenclature - Allowable Stresses and Unity Checks ................................ 416
9.2.3.4. NORS HYDR Nomenclature - Parameters ...................................................................... 417
9.2.4. NORSOK Unity Checks .......................................................................................................... 417
9.2.4.1. NORS HYDR - Design Hydrostatic Pressure ................................................................... 418
9.2.4.2. NORS HYDR - Limit Checks ........................................................................................... 418
9.2.4.3. NORS HYDR - Elastic Hoop Buckling Strength, fhe .......................................................... 419
9.2.4.4. NORS HYDR - Characteristic Hoop Buckling Strength, fh ................................................ 419
9.2.4.5. NORS HYDR - Hoop Compressive Unity Check, UCh ....................................................... 420
9.2.4.6. NORS HYDR - Combined Tension and Hydrostatic Pressure Unity Check ........................ 420
9.2.4.7. NORS HYDR - Combined Compression and Hydrostatic Pressure Unity Check ................ 421
9.3. NORSOK Joint Strength Checks (NORS JOIN) .................................................................................. 423
9.3.1. NORS JOIN Overview ............................................................................................................ 424
9.3.2. API Joint Check Report ......................................................................................................... 427
9.3.3. NORS JOIN Nomenclature ..................................................................................................... 428
9.3.3.1. NORS JOIN Nomenclature - Dimensional ...................................................................... 428
9.3.3.2. NORS JOIN Nomenclature - Acting Forces and Stresses ................................................. 429
9.3.3.3. NORS JOIN Nomenclature - Allowable Forces, Moments, Stresses and Unity Checks ....... 429
9.3.3.4. NORS JOIN Nomenclature - Parameters ........................................................................ 430
9.3.4. NORSOK Design Strengths and Unity Checks ........................................................................ 430
9.3.4.1. NORS JOIN - Chord Action Factor, Qf ............................................................................. 431
9.3.4.2. NORS JOIN - Strength Factor Qu ................................................................................... 431
9.3.4.3. NORS JOIN - Characteristic Resistances ......................................................................... 432
9.3.4.4. NORS JOIN - Combined Axial and Bending Unity Checks ............................................... 433
9.3.5. NORS JOIN - Interpolated Joints ............................................................................................ 433
10. BEAMST ISO Theory ........................................................................................................................... 435
10.1. ISO Member Code Check (ISO MEMB) .......................................................................................... 435
10.1.1. ISO MEMB Overview ........................................................................................................... 435
10.1.2. ISO Allowable Unity Check Report ...................................................................................... 441
10.1.3. ISO MEMB Nomenclature .................................................................................................... 442
10.1.3.1. ISO MEMB Nomenclature - Dimensional ..................................................................... 443
10.1.3.2. ISO MEMB Nomenclature - Acting Section Stresses ..................................................... 444
10.1.3.3. ISO MEMB Nomenclature - Design Strengths and Unity Checks ................................... 444
10.1.3.4. ISO MEMB Nomenclature - Parameters ....................................................................... 445
10.1.4. ISO Design Strengths and Unity Checks .............................................................................. 446
10.1.4.1. Design Tension Strength, Ft ....................................................................................... 446
10.1.4.2. Design Compression Strength, Fc ............................................................................... 446
10.1.4.3. Design Bending Strength, Fb ..................................................................................... 447
10.1.4.4. Design Shear Strengths, Fv and Fve ............................................................................. 448
10.1.4.5. ISO MEMB - Unity Checks ........................................................................................... 448
10.1.4.6. ISO MEMB - Combined Forces .................................................................................... 449
10.1.5. ISO Design Strengths and Unity Checks for Dented Members .............................................. 450
10.1.5.1. Dent Parameters ........................................................................................................ 450
10.1.5.2. Design Tension Strength, Ftd, for Dented Members ...................................................... 451
10.1.5.3. Design Compression Strength, Fcd, for Dented Members ............................................. 451
10.1.5.4. Design Bending Strength, Fbd, for Dented Members ................................................... 452
10.1.5.5. Design Shear Strengths, Fvd and Fved, for Dented Members ......................................... 453
10.1.5.6. ISO MEMB - Unity Checks for Dented Members ........................................................... 453
10.1.5.7. ISO MEMB - Combined Forces for Dented Members .................................................... 454
10.2. ISO Hydrostatic Member Collapse Checks (ISO HYDR) .................................................................. 456
10.2.1. ISO HYDR Overview ............................................................................................................ 456
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10.2.2. ISO Hydrostatic Unity Check Reports ................................................................................... 462
10.2.3. ISO HYDR Nomenclature ..................................................................................................... 463
10.2.3.1. ISO HYDR Nomenclature - Dimensional ...................................................................... 463
10.2.3.2. ISO HYDR Nomenclature - Acting Section Forces and Stresses ..................................... 464
10.2.3.3. ISO HYDR Nomenclature - Allowable Stresses and Unity Checks .................................. 464
10.2.3.4. ISO HYDR Nomenclature - Parameters ........................................................................ 465
10.2.4. ISO Unity Checks ................................................................................................................ 465
10.2.4.1. ISO HYDR - Design Hydrostatic Pressure ..................................................................... 466
10.2.4.2. ISO HYDR - Limit Checks ............................................................................................. 467
10.2.4.3. ISO HYDR - Elastic Hoop Buckling Strength, fhe ........................................................... 467
10.2.4.4. ISO HYDR - Characteristic Hoop Buckling Strength, fh ................................................. 468
10.2.4.5. ISO HYDR - Hoop Compressive Unity Check, UCh ........................................................ 468
10.2.4.6. ISO HYDR - Combined Tension and Hydrostatic Pressure Unity Check .......................... 469
10.2.4.7. ISO HYDR - Combined Compression and Hydrostatic Pressure Unity Check ................. 470
10.3. ISO Joint Strength Check (ISO JOIN) ............................................................................................. 473
10.3.1. ISO JOIN Overview ............................................................................................................. 473
10.3.2. ISO Joint Check Report ....................................................................................................... 476
10.3.3. ISO JOIN Nomenclature ...................................................................................................... 477
10.3.3.1. ISO JOIN Nomenclature - Dimensional ........................................................................ 478
10.3.3.2. ISO JOIN Nomenclature - Acting Forces and Stresses ................................................... 478
10.3.3.3. ISO JOIN Nomenclature - Allowable Stresses and Unity Checks ................................... 479
10.3.3.4. ISO JOIN Nomenclature - Parameters .......................................................................... 480
10.3.4. ISO Joint Strengths and Unity Checks .................................................................................. 480
10.3.4.1. ISO JOIN - Chord Action Factor, Qf .............................................................................. 480
10.3.4.2. ISO JOIN - Strength Factor Qu .................................................................................... 481
10.3.4.3. ISO JOIN - Characteristic Resistances .......................................................................... 482
10.3.4.4. ISO JOIN - Nominal Load Unity Checks ........................................................................ 483
10.3.4.5. ISO JOIN - Combined Axial and Bending Unity Checks ................................................ 483
10.3.5. ISO JOIN - Interpolated Joints .............................................................................................. 484
11. BEAMST POST Theory ....................................................................................................................... 485
11.1. POST Command Data (POST) ....................................................................................................... 485
11.1.1. POST Overview ................................................................................................................... 485
12. BEAMST Appendices ......................................................................................................................... 489
12.1. Running BEAMST ........................................................................................................................ 489
12.1.1. ASAS Files Required by BEAMST .......................................................................................... 489
12.1.2. Files required by BEAMST in Stand-Alone Mode .................................................................. 489
12.1.3. Files Produced by BEAMST .................................................................................................. 490
12.1.4. Saving Plot Files Produced by BEAMST ................................................................................ 490
12.2. Section Descriptions ................................................................................................................... 490
12.2.1. TUB - Tubes of Circular Sections .......................................................................................... 491
12.2.2. FBI - Fabricated I-Section .................................................................................................... 494
12.2.3. WF - Wide Flanged Rolled I-Section ..................................................................................... 495
12.2.4. RHS - Rolled Hollow Section ................................................................................................ 496
12.2.5. BOX - Fabricated Box Section .............................................................................................. 497
12.2.6. PRI - Solid Rectangular Section ........................................................................................... 498
12.2.7. CHAN - Channel Section ..................................................................................................... 499
12.2.8. TEE - Tee Section ................................................................................................................. 500
12.2.9. ANGL - Angle Section ......................................................................................................... 501
12.3. Graphical Display of BEAMST Results ........................................................................................... 502
12.3.1. BEAMST Plot Files ............................................................................................................... 502
12.3.2. Presenting BEAMST Results in FEMVIEW .............................................................................. 506
12.3.2.1. Member Force Results ................................................................................................ 507
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12.3.2.2. Member Unity Check Results ...................................................................................... 508
12.3.2.3. Joint Unity Check Results ........................................................................................... 509
12.4. Using BEAMST in Stand-Alone Mode ........................................................................................... 510
12.5. BEAMST References ..................................................................................................................... 511
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Chapter 1: BEAMST Introduction
BEAMST is a post-processing program designed specifically for processing the results of engineering
beam elements analyzed by ANSYS Mechanical APDL or ANSYS Asas.
There are three options available in BEAMST:
• Post-processing alone
• Post-processing plus code checking
• Stand-alone post-processing plus code checking
The post-processing facility allows individual members to be selected for further processing. This includes
the formation of factored and combined loadcases, calculation of forces and stresses at intermediate
points along the member and presentation of results on an element by element basis.
The code checking facilities include all the functionality of the standard post-processing together with
extensive code checking procedures for the following engineering codes of practice:
• American Institute of Steel Construction (AISC) Specification for Structural Steel Buildings. Allowable Stress
Design and Plastic Design.
• American Institute of Steel Construction (AISC) Load and Resistance Factor Design Specification for Structural
Steel Buildings.
• American Petroleum Institute (API) Recommended Practice for Planning, Designing, and Constructing Fixed
Offshore Platforms - Working Stress Design, RP2A-WSD.
• American Petroleum Institute (API) Recommended Practice for Planning, Designing, and Constructing Fixed
Offshore Platforms - Load and Resistance Factor Design, RP2A-LRFD.
• Danish Regulations for Pile Supported Offshore Steel Structures (DOR), comprising:
Dansk Ingeniørforening’s Code of Practice for Pile Supported Offshore Steel Structures, DS449.
Dansk Ingeniørforening’s Code of Practice for the Structural use of Steel, DS412.
• Norwegian Petroleum Directorate (NPD), Acts, regulations and provisions for the petroleum activity.
• NS3472 E Steel Structures - Design Rules.
• British Standard BS5950: Part 1: Structural use of steelwork in building.
• NORSOK: Design of Steel Structures
• International Standard ISO 19902: Petroleum and Natural Gas Industries - Fixed Steel Offshore Structures.
The program has been designed to facilitate the incorporation of other codes of practice and report
formats.
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BEAMST Introduction
The stand-alone facility includes all the above functionality together with additional input commands
to allow member geometry and results to be entered from sources other than the standard database.
This enables the comprehensive facilities of BEAMST to be used either in a design context or to process
results from other analysis systems.
For all versions the results may be written out to plotfiles for graphical display in FEMVIEW or the
database saved for use with the ASAS Visualizer.
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Chapter 2: Facilities in BEAMST
BEAMST has the following facilities:
2.1. Selection of Members and Joints
2.2. Section Properties for BEAMST
2.3. Beam Local Axes Considerations
2.4. Section Orientation
2.5. Member Stress Evaluation
2.6. Loadcase Combinations and Classification
2.7. Code Checking in BEAMST
2.8. Obtaining Results
2.1. Selection of Members and Joints
BEAMST allows selective processing of individual members and joints. This allows successive runs of
BEAMST to target problem areas, printing more detailed check data and examining the effect of local
changes in section dimensions.
The elements to be processed may be selected by reference to individual user element numbers using
the ELEM command. Elements may also be removed from a previously defined set by using a NOT ELEM
command. Used on its own the NOT ELEM command invokes all the elements except those listed.
Joints are referenced by the number of the node or, in the case of API WSD JOIN and ISO JOIN, a maximum of 3 nodes forming the joint. The elements attached to each node are assumed to be the members
forming the joint. It is possible to define which of these are chord and brace members and any elements
not to be considered as part of the joint. The joints to be processed are selected using the JOIN command
to specify the nodes included for joint checks in a similar fashion to the ELEM command above.
2.2. Section Properties for BEAMST
The calculation of extreme fiber stresses for beams requires more information than is necessary for the
basic structural analysis. The determination of forces only needs areas and inertias to be specified,
whereas the calculation of stresses in BEAMST requires section dimensions. The additional information
can be provided using the DESI command.
If sections have been used in an Asas analysis, either directly or from an external section library, the
dimensions will be automatically accessed by BEAMST. No further input is necessary (except to define
the library name, if appropriate). However, if it is required to modify those specified for the structural
definition, a DESI command is necessary. Note that changing the section may alter the section stiffness
to a degree where the analysis results become invalid. In such a case, a full re-analysis should be performed, using the updated sections.
Section types CHAN, TEE, and ANG are available only for force and stress post-processing. No facility as
yet exists for code checking these section profiles.
The conventions used for choosing which properties are used in the computations are as follows:
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Facilities in BEAMST
a. All section areas (Ax, Ay, Az) and inertias (Ix, Iy, Iz) (‘geometric properties’) available from the preceding
analysis are chosen initially. All quantities not available default to zero.
b. If sections have been utilized in an Asas analysis, section dimensions (d, b, tw, etc.) specified are chosen
initially. In the case of a TUBE element section dimensions default to those from ASAS. Any non TUBE
elements not assigned to sections will require DESI commands.
c. All section dimensions (d, b, tw, etc.) assigned using DESI commands in BEAMST override the respective
values adopted from the analysis if appropriate. Beam extreme fiber distances are based on these settings.
Flexural properties associated with DESI information will also override the respective values adopted in
(a) above. All optional properties not specified on the DESI command such as radii of gyration default
to zero at this time.
d. Any section area or inertia not available from the preceding analysis is calculated according to the section
type as described in Section Descriptions (p. 490) of this manual.
2.3. Beam Local Axes Considerations
For any beam analysis it is critical that the local axes for beams are defined correctly. When used with
Mechanical APDL, local axes are identified automatically. BEAMST uses a subset of three ASAS beam
elements; that is, BEAM, BM3D and TUBE elements. The method of defining the local axes varies according
to the beam type as follows:
1. The local X axis for all beam types is along the beam neutral axis from end1 towards end2. Thus the
moments of inertia are about the local Y and Z axes.
2. For the BEAM element the direction of the local Y and Z axes is predefined according to the orientation
of the element itself as follows:
Local Z always lies in the global XY plane with local Y positive on the positive side of the global XY
plane. If the local Y is also in the global XY plane (that is, the element is parallel to the global Z axis)
then the local Y lies in the global Y direction.
3. For the BM3D and TUBE elements the direction of the local Y and Z axes may be defined explicitly in
the ASAS geometric data for the element.
The default axes definition of the BEAM element means its use with BEAMST should be restricted to
models with the global Z vertically upwards and to the following cases:
a. A horizontal member with the section depth (d) (local Y axis) vertical.
b. A vertical member with the section depth (d) (local Y axis) in the global Y direction.
c. A sloping member with the section width (b) (local Z axis) horizontal.
For all other cases BM3D and TUBE element types should be used. A TUBE element may only be used
to model tubular elements.
2.4. Section Orientation
As a general rule the section depth (d) is parallel to the element’s local Y direction and the section
width (b) to the element’s local Z direction.
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Loadcase Combinations and Classification
For BOX, RHS and PRI the section depth (d) is always the larger dimension and the section width (b)
the smaller. For I sections, Izz should be the strong axis inertia and Iyy the weak axis inertia. BEAMST will
then assume that the web is in the local XY plane. The resulting BEAMST Izz will then equate to the Ixx
values as listed in standard section tables (and the BEAMST Iyy equates to the Iyy values).
2.5. Member Stress Evaluation
Mechanical APDL produces force and moment results at the ends of the element only. The element
nodal results may be supplemented by force, moment and stress results at discrete sections along the
element defined by the SECT command. These intermediate results are calculated from the end forces
and moments together with any applied point or distributed member loading. Intermediate results are
also calculated automatically at the position of step changes in cross-section properties.
Extreme fiber stresses are calculated depending on the cross-section type associated with the beam
(e.g. I, BOX, CHAN, etc). If sections have been utilized in an Asas analysis, the shape and dimensions
will automatically be picked up from the database. Where sections have not already been specified,
DESI commands must be included to define the additional information required. The methods used to
evaluate the stresses for each section type are detailed in Appendix D.
2.6. Loadcase Combinations and Classification
BEAMST accesses the results from the load steps analyzed in the preceding Mechanical APDL analysis.
These loadcases are referred to as basic loadcases in BEAMST. Individual basic loadcases may be selected
for processing using the CASE command.
Further loadcases may be created in BEAMST by factoring and combining the basic loadcases to form
combined loadcases. These combined cases are defined from basic loadcases using the COMB and CMBV
commands. The CMBV command allows a number of different combination methods to be used.
BEAMST processes all selected basic loadcases in increasing user loadcase number order followed by
all selected combined loadcases in the order that they are defined in.
In order to process the basic loadcases, BEAMST needs to know the origin of the loadcase. By default
this is assumed to be a static analysis. Unsigned basic loadcases from a response spectrum analysis
should be specified on a SPEC command to indicate their origin. Response spectrum loadcases may,
however, be treated as linear static if so desired.
For the purposes of checking members to AISC WSD and API design codes, (‘and joints to API’) and
joints to API any basic loadcase specified as spectral will be subject to the ‘automatic signed expansion
procedure’ described in Spectral Loadcases and ‘Automatic Signed Expansion Procedures’ (p. 153),
whereby the unsigned member forces are systematically assigned all possible signed values. For such
cases BEAMST will establish and report the signed expansion which maximizes each unity check as appropriate. When a combined loadcase has more than one spectral basic loadcase constituent the unsigned
basic loadcases are combined prior to the application of the ‘signed expansion procedure.’
If ANSYS Asas is used, combined Loadcases which involve static-spectral summation should not be
formed in a previous LOCO run. In such cases a LOCO run should be used to factor and combine the
static components and to separately include, but not combine, the spectral components. BEAMST should
then be used to combine the final static and spectral components together. This method of combining
results between LOCO and BEAMST is the most efficient way of performing such combinations. The
BYUE Option must be used in LOCO during this process.
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Facilities in BEAMST
Allowable stresses in working stress design codes may be increased above those appropriate to ‘Ordinary’
conditions for ‘Extreme’/Storm and ‘Earthquake’/Seismic conditions. Any basic loadcase or combined
loadcase selected in BEAMST for reporting may be specified as being of the Extreme or Earthquake
‘Type’ using the EXTR and QUAK commands respectively.
2.7. Code Checking in BEAMST
BEAMST may be used to assess beam structures against a number of engineering design codes.
The choice of code is made by supplying a code header command followed by data relevant for the
code check. A single BEAMST run may process a number of different code checks by simply appending
the data for each in the datafile. Details of this are given in BEAMST Command Sets (p. 54).
The code checks fall into two types, member and joint checks. Member checks examine the stress levels
within individual elements taking into account the cross-section. The stress levels are calculated at the
element ends, the position of any steps in cross-section dimension and any intermediate points specified
in the data (SECT command). The member checks consider both the static stress levels and buckling
failure modes.
It is permissible to model a physical member by several beam elements and thus the length of a
member may differ from that of an element. BEAMST will automatically determine the member length
for member checks based on the element connectivity and support conditions specified. The two ends
of a member are defined as the nodes at which one or more freedoms are suppressed or a corner or
branch is detected in the model geometry. The computed member length is employed as the default
for some length related parameters such as the unbraced length. Also, some coefficients (e.g. CMY and
CMZ) are determined from the forces or moments at the member ends together with their distributions
along the member.
Joint checks examine the stresses around the intersection of tubular members and consider such effects
as yield and punching shear.
Detailed description of each type of code check may be found from BEAMST AISC Theory (p. 129) onwards
of this manual.
2.8. Obtaining Results
Results from BEAMST may be saved to the database for subsequent presentation in FEMVIEW or the
Asas Visualizer program. Within these programs the results may be presented in two forms:
• Bending moment and shear force diagrams
• Unity check values superimposed on the mesh
Results saved to the database can also be brought into Excel using a custom plugin or through Python
functions. See the following sections for more information.
2.8.1. Accessing Results using Excel
2.8.2. Accessing Results using Python
2.8.3. BEAMST Results
2.8.1. Accessing Results using Excel
A plugin is available to allow you to access BEAMST and FATJACK results in Microsoft® Excel®. It is intended to facilitate the development of Microsoft Excel spreadsheets to present results from code
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Obtaining Results
checking. The interface consists of a series of Excel functions that can be accessed within the spreadsheet
to link to data directly in the results database.
The functions can be included in formulae just like ordinary Excel functions (such as sine, sum, max,
etc.). If you cannot remember the order or meaning of the arguments to the function, use Excel’s
function wizard - the functions are listed in a category called ASAS-Excel. All the functions have names
starting with the prefix axl.
2.8.1.1. Compatibility
The plugin is available for 32-bit and 64-bit Excel versions designed to run under Microsoft Windows.
2.8.1.2. Installing the Excel Plugin
The interface for Excel® consists of two main parts:
• A dynamic link library called axl32.dll for 32-bit versions of Excel and axl64.dll for 64-bit versions.
• An Excel® add-in macro sheet called axl32.xla for 32-bit versions of Excel and axl64.xla for 64-bit
versions.
The notes below relate to Microsoft® Excel® 2007 and 2010 on 32-bit systems. Earlier versions may vary
slightly from the suggested installation. For Excel 2010 64-bit, the same instructions apply, but the
axl64.xla and axl64.dll should be used.
To use the plugin functions, Excel needs to know the location of the XLA file and must be able to access
the axl32.dll or axl64.dll file. To make these files accessible:
axl32.dll/axl64.dll: This file is located within the installed Ansys files (default location:
C:\Program Files\Ansys Inc\version\asas\bin\platform). It must either be copied to
a location on the system path or have the above folder added to the path. You may need additional
permissions to perform either of these actions and therefore we recommend that you consult your IT
department.
axl32.xla/axl64.xla: In Excel, select Office > Excel Options > Add-Ins, then browse to the
location of the file; by default this is in the axl subfolder of the installation. Next, select Office > Excel
Options > Add-Ins > Manage Excel Add-ins and ensure the Axl32 box is selected. Ensure that these
settings are saved before closing Excel.
If you are presented with options to update links when opening an existing spreadsheet, select Don’t
Update, then copy the path preceding a command, including apostrophes and the exclamation mark,
and use Find and Replace with no entry for the Replace to remove it. Save and close your file, and this
message shouldn’t be shown again when re-opening, unless the link is modified (this may occur if you
transfer the file to another machine and the path to the XLA file is different).
If you are shown this repeatedly, it is likely that the links are not being updated correctly, so check the
path to the link in Edit > Links, ensure that only one axl32.xla file is installed on your machine,
then update the location via Tools > Add-Ins.
Test the installation by entering =AxlVersion() into a cell to ensure that you have the correct version
installed. If the result cannot be evaluated, then it is likely that the axl32.dll is not located on the system
path.
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Facilities in BEAMST
2.8.1.3. Available Function Descriptions
Many of the functions start with an argument called model in the descriptions below. This argument
defines the project and structure being investigated, and the directory in which the files are located. It
is a string consisting of three parts, separated by semi-colons:
folder;project;structure
When a Design Assessment system has been used, both the project and structure default to MECH; for
example, if your files were stored in the folder c:\user the model path would be:
C:\USER;MECH;MECH
The best way of entering this data is to enter it into a single cell of the spreadsheet, then refer to this
cell in each call of a function. Use the $ symbol to make this an absolute cell reference, or name the
cell to make it easier. The purpose of specifying the model in each call is to allow results from different
models to be intermixed in one spreadsheet at will.
FUNCTIONS
DESCRIPTION
Functions to retrieve basic model information
axlbeamaxis
Returns beam axis direction cosines
axlelementnode
Returns the value of a node number on an element
axlloadname
Returns the title of the specified loadcase number
axlloadnumber
Returns the user loadcase number of the specified internal loadcase
axlnelement
Returns the number of elements in the model
axlnload
Returns the number of loadcases on the model
axlnnode
Returns the number of nodes on the model
axlnode
Returns one of the global coordinates of a specified node
axlnodenumber
Returns the user node number
axlnumbersubsets
Returns the number of subsets for a given loadcase
axlrundate
Returns date and time of the BEAMST / FATJACK run
axlruntitle
Returns the title of the ASAS analysis
axlsubsetnumber
Returns a user subset number given a model, user loadcase and system subset number
axlunits
Returns the units associated with the analysis
axluserelement
Returns the user element number
Functions to obtain results
axlgetelement
Returns the requested element result
axlgetelementex
Returns the requested element result, extended for additional result availability
axlgetelementflt
Returns the requested element result, filtered based on the given information
axlgetequation
Returns the requested equation result
axlgetglobal
Returns the requested global result
axlgetnodal
Returns the requested nodal result
Miscellaneous functions
axlerror
8
Returns a text string describing an error code returned by a function
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Obtaining Results
FUNCTIONS
DESCRIPTION
axlversion
Returns a text string identifying the version of the add-in macro sheet (XLA file) and the
associated dynamic link library (DLL file) which are currently being used
Note
When entering string arguments to functions, they should be enclosed in double quotes.
2.8.1.3.1. Functions to Retrieve Basic Model Information
The following functions can be used to retrieve basic model information, such as the number of nodes,
elements and loadcases.
axlbeamaxis
Purpose:
Returns the direction cosine components for beam element local axes.
Syntax:
axlbeamaxis (model, element, axisname)
Notes:
axisname corresponds to the required axis direction cosine and may be one of
the following:
Mnemonic
Description
XX
Direction cosines for local X axis
YX
XZ
YX
Direction cosines for local Y axis
YY
YZ
ZX
Direction cosines for local Z axis
ZY
ZZ
The axis information returned relates to the final member orientation i.e. taking
account of any rigid offsets.
Example:
axlbeamaxis(Jacket, 1001, ”Zy”) returns the y component of the local Z
axis for element 1001 in the model defined by the named cell Jacket.
axlelementnode
Purpose:
Returns the value of a node number on an element. Nodes are returned in the same
order as they are defined in the model.
Syntax:
axlelementnode (model, element, index)
Notes:
index is the position of the node in the element definition, between 1 and the number
of nodes that the element supports.
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9
Facilities in BEAMST
Example:
axlelementnode(Jacket, 2050, 2) returns the number of the second node
on element 2050 in the model defined by the named cell Jacket.
axlloadname
Purpose:
Returns the value of a node number on an element. Nodes are returned in the same
order as they are defined in the model.
Syntax:
axlloadname (model, loadcase)
Notes:
loadcase is the user defined loadcase number.
Example:
axlloadname(Jacket, 10) returns the title of loadcase 10 in the model defined
by the named cell Jacket.
axlloadnumber
Purpose:
Purpose: Returns the user loadcase number of the specified internal loadcase.
Syntax:
axlloadnumber (model, loadcaseindex)
Notes:
The purpose of this function is to allow users to generate a list of all the load cases on
the model by creating a table with one column containing the sequence 1, 2, 3, ... and
the next column using this function to determine the load case number. See also
axlnload (p. 10).
Example:
axlloadnumber(Jacket, 2) returns the user loadcase number corresponding to
the second loadcase for the model defined by the named cell Jacket.
axlnelement
Purpose:
Returns the number of elements in the model.
Syntax:
axlnelement (model)
Notes:
This function will exclude any components that have been defined in the model.
Example:
axlnelement(Jacket) returns the number of elements in the model defined by
the named cell Jacket.
axlnload
Purpose:
Returns the number of loadcases on the model.
Syntax:
axlnload (model)
Notes:
May be useful used in conjunction with axlloadnumber above to generate a list of user
loadcase numbers.
Example:
axlnload(Jacket) returns the number of loadcases in the model defined by the
named cell Jacket.
axlnnode
Purpose:
Returns the number of nodes on the model.
Syntax:
axlnnode (model)
Notes:
Nodes are counted on the basis of generating equations in the stiffness matrix, so nodes
which are only used as guide points to define local axes or skew systems are not included.
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Obtaining Results
Example:
axlnnode(Jacket) returns the number of structural nodes in the model defined
by the named cell Jacket.
axlnode
Purpose:
Returns one of the global coordinates of a specified node.
Syntax:
axlnode (model, nodenumber, axis)
Notes:
axis may be specified by name (“X”, “Y” or “Z”) or by number (1, 2 or 3).
Example:
axlnode(Jacket, 1010, ”y”) returns the y global coordinate for node 1010 in
the model defined by the named cell Jacket.
axlnodenumber
Purpose:
Returns the user node number by reference to an index in increasing node number
order.
Syntax:
axlnodenumber (model, index)
Notes:
index alludes to the reference to a given node within a list of ascending user node
numbers. index should be between 1 and the number of nodes in the model; see
axlnnode (p. 10).
Example:
axlnodenumber(Jacket, 216) returns the node number at position 216 of the
sorted node number list for the model defined by the named cell Jacket.
axlnumbersubsets
Purpose:
Returns the number of subsets which constitute a loadcase.
Syntax:
axlnumbersubsets (model,loadcase)
Notes:
The function returns the number of subsets within a loadcase of a model, for example
when a transient analysis is being code checked.
Example:
axlnumbersubsets(Pile, 4) returns the number of subsets contained within
the fourth load of the model defined by Pile.
axlrundate
Purpose:
Returns the date and time for a given analysis.
Syntax:
axlrundate (model)
Notes:
The function returns a 17 character text string containing the date and time in the form
“08.41 1-JUL-97”.
Example:
axlrundate(Jacket) returns the date and time information for the model defined
by the named cell Jacket.
axlruntitle
Purpose:
Purpose: Returns the title used for a given analysis.
Syntax:
axlruntitle (model)
Notes:
This function returns an 81 character text string containing the title in the form “Example
2.1 Extreme Wave Analysis”.
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Facilities in BEAMST
Example:
axlruntitle(Jacket) returns the title for the model defined by the named cell
Jacket.
axlsubsetnumber
Purpose:
Returns the user number of a subset.
Syntax:
axlsubsetnumber (model,loadcase,subset)
Notes:
The function returns the user number of a subset denoted by its model, load and system
subset number.
Example:
axlsubsetnumber(Jacket, 6, 2) returns the user subset number of the second
subset contained within the sixth load of the model defined by Jacket.
axlunits
Purpose:
Returns the user number of a subset.
Syntax:
axlunits (model, unitname)
Notes:
unitname refers to the particular unit type required and may be one of the following:
FORCE
LENGTH
ROTATION
MASS
TEMPERATURE
TIME
Abbreviations are permitted; for example: F, FOR, FORCE will all retrieve the force
unit.
If units were not used in the analysis an appropriate error message is returned.
The function returns a 13-character unit name.
Example:
axlunits(Jacket, ”length”) returns the length unit the model defined by the
named cell Jacket.
axluserelement
Purpose:
Returns the user element number by reference to an index in increasing user element
order.
Syntax:
axluserelement (model, index)
Notes:
index alludes to the reference to a given element within a list of ascending user element numbers. index should be between 1 and the number of elements in the
model; see axlnelement (p. 10). Components are excluded from this list.
Example:
axluserelement(Jacket, 115) returns the user element number at position
115 of the sorted user element list for the model defined by the named cell Jacket.
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Obtaining Results
2.8.1.3.2. Results Database Functions
These functions allow access to results from BEAMST, FATJACK and Soil-Pile-Structure Analyses. See
BEAMST Results, FATJACK Results, and Soil-Pile-Structure Results for a description of the result type and
result component referred to in the following function definitions.
axlgetelement
Purpose:
Returns the requested element result.
Syntax:
axlgetelement (model, element, load, subset, result type, result component, surface, node )
Notes:
The result type and result component indicate which information will be retrieved.
For example the result type may be “stress” and the result component “sxx”, “syy”,
“szz”, and so on. The result type and component can be entered as upper or lower
case. An element may have more than one surface or node and therefore the
surface number and node must be entered in this function. Zero should be entered
for subset if the load contains no subsets.
In instances where beam type elements have results at section positions along
their length, the node field is used to identify the section positions. Care should
be taken if section steps are used, as two results will be generated at these positions, one on either side of the step. For example, if you have a 10m long tube,
with a section change at 2m from one end, and section results are requested at
10% intervals, you will have twelve result positions ( two at the ends, nine at intermediate points, one at the step).
Example:
axlgetelement(Jacket, 35, 2, 10, “force/moment”, “x”,1,3) returns
the force in the x direction at the third node on the first surface of element 35. The
results are retrieved for the tenth subset of loadcase 2 within the model referenced by
the named cell Jacket.
axlgetelementex
Purpose:
Returns the requested element result, extended for additional result availability.
Syntax:
axlgetelementex (model, element, load, subset, result type, result component, surface, node, result position)
Notes:
This is an extended version of axlgetelement; all input is the same as that except for
the additional result position. This is used for results where there are multiple values
of a result; for example, STRESS in a time history based FATJACK analysis with rainflow
counting.
Example:
axlgetelementex(“C:\;ABCD;WXYZ”, 72, 11, 1, “RANGE HISTOGRAM”,
“STRESS”,1,2,10) returns the 10th STRESS in the RANGE HISTOGRAM values at
the second node on the first surface of element 72. The results are retrieved for loadcase
11, subset 1 within the project ABCD, structure WXYZ, located in C:\.
axlgetelementflt
Purpose:
Returns the requested element result, filtered based on the given information.
Syntax:
axlgetelementflt (model, element, load, subset, result type, result component, surface, node, result position, filter type, return type)
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Facilities in BEAMST
Notes:
This is an extended version of axlgetelement (p. 13); however it allows for the filtering of a range of values to be obtained. Model, result type, result position and
result component all function as per axlgetelementex (p. 13). The filtering is controlled by the filter type and requested value, for which the following should be
entered:
Filter Type
Filtering Algorithm
1
Maximum
2
Minimum
3
Absolute Maximum (i.e. furthest from zero)
4
Absolute Minimum (i.e. closest to zero)
Return Type
Returned Result
1
Value of Result
2
Element Number at which the value can be found
3
Load Case / Set for which the value can be found
4
Load Subset for which the value can be found
5
Surface at which the value can be found
6
Local node at which the value can be found
Element, load, subset, surface and node should have either a particular value assigned to limit the searching to a particular set of results, or -1 entered to loop
over each result available. For example, entering a loadcase of -1 will mean that
all loadcases will be searched according to the filter type and requested value.
Example:
axlgetelementflt(“C:\;ABCD;WXYZ”, -1, 100, 0, “API LRFDALLOED1
UC”, “UC.AXIAL”,1,-1,1,2,1) returns the maximum unity check value for all
positions on all elements for loadcase 100. The results are retrieved for the project
ABCD, structure WXYZ, located in C:\.
axlgetequation
Purpose:
Returns the requested equation result.
Syntax:
axlgetequation (model, node, load, subset, result type, result component)
Notes:
The result type and result component indicate which information will be retrieved. For
example the result type may be “displacement” and the result component “x”, “y”, “z”,
and so on. The result type and component can be entered as upper or lower case. Zero
should be entered for subset if the load contains no subsets.
Example:
axlgetequation(Rig, 2, 3, 0, “displacement”, “y”) returns the displacement in the y direction at the second node of loadcase 3 within the model “Rig”.
axlgetglobal
Purpose:
Returns the requested global result.
Syntax:
axlgetglobal (model, load, subset, result type, result component)
Notes:
Global results are specific to the load case and/or subset and not to a certain element
or node. The result type and result component indicate which information will be retrieved. For example the result type may be “reaction sum” and the result component
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“x”, “y”, “z”, and so on. The result type and component can be entered as upper or
lower case. Zero should be entered for subset if the load contains no subsets.
Example:
axlgetglobal(Jacket, 10, 0, “prescribed reac sum”, “z”) returns
the prescribed reaction global sum in the z direction for loadcase 10 within the model
“Jacket”.
axlgetnodal
Purpose:
Returns the requested nodal result.
Syntax:
axlgetnodal (model, node, load, subset, result type, result component,
freedom)
Notes:
Nodal results are generally concerned with the history of the displacement, velocity
and acceleration of a node. The result type and result component indicate which information will be retrieved. For example the result type may be “history displacement”
and the result component “x”, “y”, “z” or “time”, and so on. The result type and component can be entered as upper or lower case. Zero should be entered for subset if the
load contains no subsets. For example, if “max displacement” is entered as a result type
this will retrieve the maximum displacement from all the loadcases, and therefore the
loadcase should be entered as one and the subset zero. The freedom input indicates
which freedom (“x”, “y”, “z” for example), to retrieve for a particular result type (“max
displacement” for example).
Example:
axlgetnodal(Rig, 12, 1, 0, “max acceleration”, “time”, 2) returns
the time at which the maximum acceleration occurred for freedom number 2 when
considering all loadcases within the results set.
2.8.1.3.3. Miscellaneous Functions
axlerror
Purpose:
Returns a text string describing an error code returned by a function.
Syntax:
axlerror (error)
Notes:
The description may be useful in determining the cause of a problem.
Example:
axlerror (302)
or:
axlerror (“axl:302”)
will return the description: “AXL: invalid element number”. This function should
only be used when another function in a cell displays a message of the form axl:nnn
where nnn is an error number. For example, if cell C22 is showing axl:302, then
typing:
=axlerror(C22)
in an empty cell will show a description of the error, as above.
axlversion
Purpose:
Returns a text string identifying the version of the add-in macro sheet axl.xla and the
associated dynamic link library axl.dll which are currently being used. This is mainly
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15
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intended so that support personnel can identify possible problems due to the use of
out-of-date software.
Syntax:
axlversion ( )
Notes:
This returns a string something like:
“axl.xla version 12.00.01.0, axl.dll version 12.00.01.0”
Note that the function does not require an argument.
Example:
Not required.
2.8.2. Accessing Results using Python
The following two functions have been added to the axl32 and axl64 dll’s to allow access to the database from within a python scripting environment, such as the one used with Design Assessment.
The Python scripts (located in the \v150\asas\DesignAssessment folder in the ANSYS installation)
provided as part of the Design Assessment Beamcheck capability can be modified to your requirements:
for example, to incorporate further analysis of results and presentation of specific requirements
pyGetElementersultFlt
pyGetElementersultFlt(project,pyelement,pyload,pysubset,pyrestype,pyrescomp,byref(result),byref(intorreal),pysurface,pynode,pyrespos,pyFltType,pyFltReturn)
This is similar to the function GetElementersultFlt, and the inputs/outputs are detailed below. It allows
access to obtain a specific result on a specific element of the model. If the same result is to be obtained
for all elements, and fine control over exactly what is retrieved is needed, pyGetElementersultArray
should be used for efficiency.
Name
Type
Description
project
c_char_p
The path to the project; for example, c:\MyProject\ThisProject;MECH;MECH would look for the MECH10 and MECH45 files in the
folder c:\MyProject\ThisProject
pyelement
c_long
Element number; use -1 to filter over all elements
pyload
c_long
Loadcase/loadset number; use -1 to filter over all loadcases
pysubset
c_long
Load subset; use -1 to filter over all subsets
pyrestype
c_char_p
Result Type; see ASAS Database manual for details
pyrescomp
c_char_p
Result Component; see ASAS Database manual for details
result
c_double
Output, passed by reference (i.e. use byref()); this is the result value returned
intorreal
c_long
Output, passed by reference; 1 if it’s a number, 0 if it’s a text result
pysurface
c_long
Surface on which the result is to be obtained; use -1 to filter over all surfaces
pynode
c_long
Local element node that the result is to be obtained; use -1 to filter over all
nodes
pyrespos
c_long
Result position; only used for FATJACK, to indicate the interval
pyFltType
c_long
Type of filtering to use:
1 – max
16
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Obtaining Results
Name
Type
Description
2 – min
3 – abs max
4 – abs min
pyFltReturn
c_long
Result item to return:
1 – value
2 – element number at which value can be found
3 – loadcase/loadset at which the value can be found
4 – load subset at which the value can be found
5 – Surface at which the value can be found
6 – local node at which the value can be found
pyGetElementersultArray
pyGetElementersultArray(project,pyFirstload,pyLastload,pyConstantLoad,pyIsLC,pyStepsElems,pyrestype,pyrescomp, pyrespos,byref(Resrecord),byref(LCrecord),byref(Elrecord))
This function enables a result for all the elements in the model to be obtained. The maximum value of
the result over each node and surface is always selected. If finer control is required, then pyGetElementersultFlt can be used.
Name
Type
Description
project
c_char_p
The path to the project; for example, c:\MyProject\ThisProject;MECH;MECH would look for the MECH10 and MECH45 files
in the folder c:\MyProject\ThisProject.
pyFirstload
c_long
First loadcase/loadset (if pyIsLC is true) or subset (if pyIsLC is false)
to loop from.
pyLastload
c_long
Last loadcase/loadset (if pyIsLC is true) or subset (if pyIsLC is false)
to loop to.
pyConstantLoad
c_long
Constant loadcase/loadset (if pyIsLC is false) or subset (if pyIsLC is
true).
pyIsLC
c_bool
Used in conjunction with pyFirstLoad, pyLastLoad and pyConstantLoad to control the contents and size of the results being obtained.
pyStepsElems
c_long
Size of the arrays that are populated with results; typically number
of elements * (pyLastload- pyFirstload).
pyrestype
c_char_p
Result Type; see ASAS Database manual for details.
pyrescomp
c_char_p
Result Component; see ASAS Database manual for details.
pyrespos
c_long
Result position; only used for FATJACK, to indicate the interval.
Resrecord
array of c_doubles,
the size of
pyStepsElems
Passed by reference; values returned by function will be available
here. The array needs to have the double value defined in a class;
see the FATJACK or BEAMST evaluate python script for an example.
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Name
Type
Description
LCrecord
array of c_doubles,
the size of
pyStepsElems
Passed by reference; corresponding loadcase or subset (determined
by pyIsLC) returned by function will be available here.
Elrecord
array of c_doubles,
the size of
pyStepsElems
Passed by reference; corresponding element returned by function
will be available here.
2.8.3. BEAMST Results
Only element results (p. 13) are saved by BEAMST. Result types depend on the type of processing carried
out. The 20 character results type is divided into 2 sections: the first 16 characters represent the type
of processing carried out, and the final 4 characters represent the type of result stored.
The 16 character string representing the processing type is split into 4*4 character substrings. These
16 character strings are tabulated below and are based on the BEAMST header commands. Refer to
BEAMST Command Reference (p. 51) for full details of the meaning of these character strings. Note that
the ^ character indicates that a blank space must be entered.
AISC
WSD^
ALLO
ED8^
ED9^
API^
LRFD
MEMB
ED2^
WSD^
ALLO
ED13
HYDR
ED16
NOMI
ED17
PUNC
ED18
ED19
ED20
ALLO
ED21
HYDR
JOIN
LRFD
ALLO
ED1^
HYDR
NOMI
BS59
^^^^
MEMB
^^^^
DS44
HIGH
MEMB
A0^^
NORM
A^^^
B^^^
C^^^
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D^^^
ISO^
HIGH
NOMI
A^^^
^^^^
MEMB
ED1^
HYDR
JOIN
NPD^
^^^^
MEMB
ED92
PUNC
NORS
^^^^
MEMB
ED98
HYDR
JOIN
POST
^^^^
^^^^
^^^^
The following sections describe the results available for the final 4 characters entered.
2.8.3.1. Member Properties
2.8.3.2. Member Forces
2.8.3.3. Member Stresses
2.8.3.4. AISC WSD and LRFD Member Unity Checks
2.8.3.5. API WSD and LRFD Member Unity Checks
2.8.3.6. API WSD and LRFD HYDR Checks
2.8.3.7. API WSD NOMI/JOIN Checks
2.8.3.8. API WSD and LRFD PUNC Checks
2.8.3.9. API LRFD Joint Checks
2.8.3.10. BS5950 Member Checks
2.8.3.11. DS449 Member Checks
2.8.3.12. DS449 Joint Checks
2.8.3.13. NPD Member Checks
2.8.3.14. NPD Joint Checks
2.8.3.15. NORSOK Member Checks
2.8.3.16. NORSOK HYDR Checks
2.8.3.17. NORSOK Joint Checks
2.8.3.18. ISO Member Checks
2.8.3.19. ISO HYDR Checks
2.8.3.20. ISO Joint Checks
2.8.3.1. Member Properties
Characters 17-20 of the results type for member properties are always PROP.
The results components available are dependent on the type of cross-section, and are listed below.
RESULTS
COMPONENT
DESCRIPTION
SECTION TYPE
NO.STEPS
Number of Steps
ALL
NO.PR.ST
Number of Properties on
Step
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Facilities in BEAMST
RESULTS
COMPONENT
DESCRIPTION
SECTION TYPE
SEC.TYPE
Section Type
SEC.POSN
Section Position on Element
LENGTH
Length of element
EFF.LN_Y
Y Effective Length
EFF.LN_Z
Z Effective Length
UNBR.L_Y
Y Unbraced Length
UNBR.L_Z
Z Unbraced Length
REL.SR_Y
Y Slenderness Ratio
REL.SR_Z
Z Slenderness Ration
AREA
Section Area
AVY
Y Shear Area
AVZ
Z Shear Area
J
Torsional Inertia
IYY
Y Bending Inertia
IZZ
Z Bending Inertia
DENT_Y
Dent depth, Y
DENT_Z
Dent depth, Z
IMPS_Y
Out of straightness, Y
IMPS_Z
Out of straightness, Z
DIAM
Tube diameter
TUBE
THICK
Wall thickness
TUBE, RHS, CHANNEL
DEPTH
Section Depth
W.FLANGE, RHS, FAB.BOX, PRISM, FAB.I, CHANNEL,
TEE, ANGLE
WIDTH
Section Width
W.FLANGE, RHS, FAB.BOX, PRISM, CHANNEL, TEE,
ANGLE
FLANGE.T
Thickness of Flanges
W.FLANGE, CHANNEL, TEE, ANGLE
WEB.T
Thickness of Web
W.FLANGE, FAB.I, CHANNEL, TEE, FAB.BOX
BOT.FL.W
Width of Bottom Flange
FAB.I
BOT.FL.T
Thickness of Bottom
Flange
FAB.I, FAB.BOX
TOP.FL.W
Width of Top Flange
FAB.I
TOP.FL.T
Thickness of Top Flange
FAB.I, FAB.BOX
TUBE – only if DENT data supplied
2.8.3.2. Member Forces
Characters 17-20 of the results type for member forces are always FORC.
The results components define the component of force and are as tabulated below.
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RESULTS COMPONENT
DESCRIPTION
SEC.POSN
Section position from end 1 of beam
FXX
X force (axial)
FQY
Y shear force
FQZ
Z shear force
TXX
Torsional moment
MYY
Y bending moment
MZZ
Z bending moment
FREE.MY
Free moment Y direction
FREE.MZ
Free moment Z direction
2.8.3.3. Member Stresses
Characters 17-20 of the results type for member stresses are always STRS.
The results components define the component of stress and are as tabulated below; some components
are available only for tubular sections (T), some are available only for beams (B).
RESULTS COMPONENT
DESCRIPTION
SEC.POSN
Section position from end 1 of beam
SAX
Axial stress
SVY
Y shear stress
SVZ
Z shear stress
SVT
Torsion stress (T)
SBY
Y bending stress (T)
SBZ
Z bending stress (T)
SBY_C
Y Compressive bending stress (B)
SBZ_C
Z Compressive bending stress (B)
SBY_T
Y Tensile bending stress (B)
SBZ_T
Z Tensile bending stress (B)
SV.MAX
Max. Shear stress (T)
SXX.A
Stress at location A
SXX.B
Stress at location B
SXX.C
Stress at location C
SXX.D
Stress at location D
2.8.3.4. AISC WSD and LRFD Member Unity Checks
Characters 17-20 of the results type for member unity checks are always ^^UC.
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2.8.3.4.1. AISC WSD Checks
The results components for WSD 8th and 9th edition checks are as tabulated below; components marked
* are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
T/C
Tension / Compression *
CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
SEC.POSN
Section position
CMY
Y amplification reduction factor
CMZ
Z amplification reduction factor
AL.SAX
Allowable axial stress
AL.SV
Allowable shear stress
AL.SBY
Allowable Y-bending stress
AL.SBZ
Allowable Z-bending stress
UC.AXIAL
Axial unity check
UC.SHR_Y
Y shear unity check
UC.SHR_Z
Z shear unity check
UC.BND_Y
Y bending unity check
UC.BND_Z
Z bending unity check
UC.SHEAR
Max. shear unity check
UC.BUCKL
Buckling unity check
UC.BUCSR
Buckling CSR unity check
UC.YIELD
Yield unity check
2.8.3.4.2. AISC LRFD Checks
The results components for LRFD 2nd edition checks are as tabulated below; components marked * are
stored as character strings.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
T/C
Tension / Compression *
CODE
Alpha codes *
MESSAGE1
Message 1 *
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RESULTS COMPONENT
DESCRIPTION
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
SEC.POSN
Section position
CMY
Y amplification reduction factor
CMZ
Z amplification reduction factor
AL.SAX
Allowable axial stress
AL.SCR
Critical stress
AL.SEULY
Allowable Y Euler buckling stress
AL.SEULZ
Allowable Z Euler buckling stress
AL.SVY
Allowable Y shear stress
AL.SVZ
Allowable Z shear stress
AL.SBY
Allowable Y bending stress
AL.SBZ
Allowable Z bending stress
UC.AXIAL
Axial unity check
UC.SHR_Y
Y shear unity check
UC.SHR_Z
Z shear unity check
UC.BND_Y
Y bending unity check
UC.BND_Z
Z bending unity check
UC.BUCSR
Buckling CSR unity check
UC.YIELD
Yield unity check
2.8.3.5. API WSD and LRFD Member Unity Checks
Characters 17-20 of the results type for member unity checks are always ^^UC.
2.8.3.5.1. API WSD Checks
The results components for WSD checks are as tabulated below; components marked * are stored as
character strings. Some results components are available for some member types or editions only—see
DESCRIPTION column.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
SPEC.CSE
Spectral case *
T/C
Tension / Compression *
CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
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RESULTS COMPONENT
DESCRIPTION
SEC.POSN
Section position
CMY
Y amplification reduction factor
CMZ
Z amplification reduction factor
CB.BEND
Critical buckling (Bending)
AL.SAX
Allowable axial stress
AL.SV
Allowable shear stress
AL.SBY
Allowable Y-bending stress (not TUBE ed17 on)
AL.SBZ
Allowable Z-bending stress (not TUBE ed17 on)
UC.AXIAL
Axial UC
UC.SHR_Y
Y shear UC (not TUBE ed17 on)
UC.SHR_Z
Z shear UC (not TUBE ed17 on)
UC.BND_Y
Y bending unity check
UC.BND_Z
Z bending unity check
UC.BUCKL
Buckling unity check
UC.BUCSR
Buckling CSR unity check
UC.YIELD
Yield unity check
UC.SHEAR
Max. shear unity check (TUBE ed13 only)
AL.SVT
Allowable torsion stress (TUBE ed17 on)
AL.SB
Allowable bending stress (TUBE ed17 on)
UC.SHEAR
Flexural shear unity check (TUBE ed17 on)
UC.TORSN
Torsional shear unity check (TUBE ed17 on)
UC.BEND
Resultant bending unity check (TUBE ed17 on)
2.8.3.5.2. API WSD Checks (Spectral)
Spectral results are stored as 4 sets of information corresponding to the four reports as listed in Unity
Check Report for Shear, Pure Bending and Yield Unity Checks (p. 219). The first three sets of results
(Highest Shear Unity Check, Highest Pure Bending Unity Check and Highest Yield Unity Check) are stored
under results components as above, with the ^^UC in characters 17-20 of the results type changed to
S1UC, S2UC, S3UC respectively. The fourth set of results (Highest Buckle Unity Check) is stored under
S4UC with results components as below.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
SPEC.CSE
Spectral case *
T/C
Tension / Compression *
CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
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RESULTS COMPONENT
DESCRIPTION
MESSAGE3
Message 3 *
MESSAGE4
Message 4 *
P/F.IND
Pass/fail indicator
CMY
Y amplification reduction factor
CMZ
Z amplification reduction factor
AL.SAX
Allowable axial stress
AL.SBY
Allowable Y-bending stress (not TUBE ed16 on)
AL.SBZ
Allowable Z-bending stress (not TUBE ed16 on)
AL.SEULY
Allowable Euler buckling stress Y
AL.SEULZ
Allowable Euler buckling stress Z
SAX
Max. axial stress
SBY
Max. Y bending stress
SBZ
Max. Z bending stress
UC.AXIAL
Axial unity check
UC.BND_Y
Y bending unity check (not TUBE)
UC.BND_Z
Z bending unity check (not TUBE)
UC.BUCSR
Buckling CSR unity check
UC.BEND
Bending unity check (TUBE)
2.8.3.5.3. API LRFD Checks
The results components for API LRFD checks are as tabulated below; components marked * are stored
as character strings.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
T/C
Tension / Compression *
CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
SEC.POSN
Section position
CMY
Y amplification reduction factor
CMZ
Z amplification reduction factor
LAMBDA
Column slenderness parameter
AL.SAX
Allowable axial stress
AL.SV
Allowable shear stress
AL.SVT
Allowable torsion stress
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RESULTS COMPONENT
DESCRIPTION
AL.SB
Allowable bending stress
AL.SEULY
Allowable Y Euler buckling stress
AL.SEULZ
Allowable Z Euler buckling stress
YIELD
Yield stress
BUCKLE
Buckle stress
UC.AXIAL
Axial unity check
UC.SHEAR
Shear unity check
UC.TORSN
Torsion unity check
UC.BND_Y
Y bending unity check
UC.BND_Z
Z bending unity check
UC.BEND
Resultant bending unity check
UC.BUCKL
Buckling unity check
UC.BUCSR
Buckling CSR unity check
UC.YLD1
Yield unity check
UC.YLD2
Yield unity check
2.8.3.6. API WSD and LRFD HYDR Checks
Characters 17-20 of the results type for hydrostatic unity checks are always ^^UC.
2.8.3.6.1. WSD Checks
The API HYDR results components are the same for all WSD editions—these are tabulated below. Only
tubular sections can be subject to hydrostatic checks; components marked * are stored as character
strings.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
T/C
Tension / Compression *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
SEC.POSN
Section position
HYD.DPTH
Hydrostatic depth
SHP
Hoop stress
AL.SAX_T
Allowable axial tension stress
AL.SAX_E
Allowable elastic axial stress
AL.SHP_E
Allowable elastic hoop stress
AL.SAX_I
Allowable inelastic axial stress
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RESULTS COMPONENT
DESCRIPTION
AL.SHP_I
Allowable inelastic hoop stress
UC.TENS
Axial tension unity check
UC.HOOPC
Hoop unity check
UC.C1
Combined unity check 1
UC.C2
Combined unity check 2
UC.C3
Combined unity check T
2.8.3.6.2. LRFD Checks
The API HYDR results components for the LRFD checks are tabulated below. Only tubular sections can
be subject to hydrostatic checks; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
SEC.POSN
Section position
HYD.DPTH
Hydrostatic depth
GAMMAD
Hydrostatic pressure load factor
GOMPAR.M
Geometry parameter
HBUC.COF
Hoop buckling coeff.
SHP
Hoop stress
AL.SAX
Allowable axial stress
AL.SB
Allowable bending stress
AL.SAX_E
Allowable elastic axial stress
AL.SHP_E
Allowable elastic hoop stress
AL.SAX_I
Allowable inelastic axial stress
AL.SHP_I
Allowable inelastic hoop stress
UC.AXIAL
Axial unity check
UC.HOOPC
Hoop unity check
UC.YIELD
Yield unity check
UC.BUCKL
Buckling unity check
UC.COMB
Combined unity check
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2.8.3.7. API WSD NOMI/JOIN Checks
2.8.3.7.1. Edition 16 to Edition 20
Characters 17-20 of the results type for nominal joint checks are always ^^UC.
The API NOMI results components are tabulated below; only tubular sections can be subject to nominal
joint checks. Only editions 16 to 20 are valid; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE1
Joint 1 type
JT.TYPE2
Joint 2 type
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
PROP.JT1
Proportion of joint 1
PROP.JT2
Proportion of joint 2
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
GAP
Gap
BETA
Beta factor
TAU
Tau factor
THETA
Theta
SAXCH
Chord stress
YIELDCH
Chord yield
AL.SVP
AISC allowable punching shear stress
SAXBR
Brace axial stress
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
QF.AXIAL
Axial QF factor
QF.IPLAN
In-plane QF factor
QF.OPLAN
Out-of-plane QF factor
QU.AX1
Axial QU factor brace 1
QU.IP1
In-plane bending QU factor brace 1
QU.OP1
Out-of-plane bending QU factor brace 1
QU.AX2
Axial QU factor brace 2
QU.IP2
In-plane bending QU factor brace 2
QU.OP2
Out-of-plane bending QU factor brace 2
FXX
Axial force
MIP
In-plane bending force
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RESULTS COMPONENT
DESCRIPTION
MOP
Out-of-plane bending force
AL.FXXB1
Allowable axial force brace 1
AL.MIPB1
Allowable in-plane bending force brace 1
AL.MOPB1
Allowable out-of-plane bending force brace 1
AL.FXXB2
Allowable axial force brace 2
AL.MIPB2
Allowable in-plane bending force brace 2
AL.MOPB2
Allowable out-of-plane bending force brace 2
UC.AXIAL
Axial unity check
UC.IP
In-plane bending unity check
UC.OP
Out-of-plane bending unity check
UC.BEND
Bending unity check
UC.AX+BN
Combined axial + bending unity check
UC.JOIN
Joint strength unity check
2.8.3.7.2. Edition 21 Onwards
Characters 17-20 of the results type for joint checks are always ^^UC.
The API JOIN check results components are tabulated below; only tubular sections can be subject to
joint checks. Only editions 21 onwards are valid; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
MESSAGE1
Messages *
MESSAGE2
Messages *
MESSAGE3
Messages *
AL.PA
Allowable Pa
AL.MAIP
Allowable Ma i/plane
AL.MAOP
Allowable Ma o/plane
BETA
Beta factor
GAMMA
Gamma ratio
TAU
Tau ratio
THETA
Theta angle
CHORD
1st chord member
CHOR.PC
Chord axial force
CHOR.MIP
Chord Moment i/plane
CHOR.MOP
Chord moment o/plane
CHOR.MP
Chord capacity
CHOR.PY
Chord strength
CHOR.DIA
Chord diameter
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RESULTS COMPONENT
DESCRIPTION
CHOR.THK
Chord thickness
FXX
Brace axial force
MIP
Brace Moment i/plane
MOP
Brace Moment o/plane
BRAC.DIA
Brace Diameter
BRAC.THK
Brace Thickness
SPEC.CSE
Spectral Loadcase expansion code *
The components for each joint type assessment for axial loading are as
follows. For joint types 2 – 5 just replace the digit at the end of the component name
Components
for joint type 1
JT.TYPE1
Joint type (Y/K/X) *
PROP.JT1
Joint proportion (%)
BAL.JT1
Balancing member no. (not applicable for Y joints)
QU.AX1
Axial Qu factor
QF.AX1
Axial Qf factor
GAP.JT1
Gap factor. The gap factor value depends on the joint type, the result
is as follows:
X joints – Qb value for brace in compression, e/D ratio for brace in
tension
K joints – gap value
Y joints – Not applicable
Components
for bending
results
QU.IP
Qu factor, i/plane
QU.OP
Qu factor, o/plane
QF.BND
Qf factor
Unity check results
UC.AXIAL
Axial capacity unity check
UC.IP
Bending i/p capacity unity check
UC.OP
Bending o/p capacity unity check
UC.AX+BN
Combined forces capacity unity check
30
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Obtaining Results
2.8.3.8. API WSD and LRFD PUNC Checks
Characters 17-20 of the results type for joint punching unity checks are always ^^UC.
2.8.3.8.1. WSD Checks
The API PUNC results components are valid up to and including the 20th edition and are tabulated
below. Only tubular sections can be subject to joint punching checks; components marked * are stored
as character strings.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE1
Joint 1 type
JT.TYPE2
Joint 2 type
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
PROP.JT1
Proportion of joint 1
PROP.JT2
Proportion of joint 2
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
GAP
Gap
BETA
Beta factor
TAU
Tau factor
THETA
Theta
SAXCH
Chord stress
YIELDCH
Chord yield
AL.SVP
AISC allowable punching shear stress
SAXBR
Brace axial stress
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
QF.AXIAL
Axial QF factor
QF.IPLAN
In-plane QF factor
QF.OPLAN
Out-of-plane QF factor
QQ.AX1
Axial QQ factor brace 1
QQ.IP1
In-plane bending QQ factor brace 1
QQ.OP1
Out-of-plane bending QQ factor brace 1
QQ.AX2
Axial QQ factor brace 2
QQ.IP2
In-plane bending QQ factor brace 2
QQ.OP2
Out-of-plane bending QQ factor brace 2
SAX
Axial stress
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RESULTS COMPONENT
DESCRIPTION
SIP
In-plane bending stress
SOP
Out-of-plane bending stress
AL.SAXB1
Allowable axial stress brace 1
AL.SIPB1
Allowable in-plane bending stress brace 1
AL.SOPB1
Allowable out-of-plane bending stress brace 1
AL.SAXB2
Allowable axial stress brace 2
AL.SIPB2
Allowable in-plane bending stress brace 2
AL.SOPB2
Allowable out-of-plane bending stress brace 2
UC.AXIAL
Axial unity check
UC.IP
In-plane bending unity check
UC.OP
Out-of-plane bending unity check
UC.BEND
Bending unity check
UC.AX+BN
Combined axial + bending unity check
UC.JOIN
Joint strength unity check
2.8.3.8.2. LRFD Checks
The API PUNC results components are tabulated below. Only tubular sections can be subject to joint
punching checks; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE1
Joint 1 type
JT.TYPE2
Joint 2 type
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
PROP.JT1
Proportion of joint 1
PROP.JT2
Proportion of joint 2
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
GAP
Gap
BETA
Beta factor
TAU
Tau factor
THETA
Theta
SAXCH
Chord stress
YIELDCH
Chord yield
AL.SVP
AISC allowable stress
SAXBR
Brace axial stress
32
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RESULTS COMPONENT
DESCRIPTION
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
QF.AXIAL
Axial QF factor
QF.IPLAN
In-plane QF factor
QF.OPLAN
Out-of-plane QF factor
QQ.AX1
Axial QQ factor brace 1
QQ.IP1
In-plane bending QQ factor brace 1
QQ.OP1
Out-of-plane bending QQ factor brace 1
QQ.AX2
Axial QQ factor brace 2
QQ.IP2
In-plane bending QQ factor brace 2
QQ.OP2
Out-of-plane bending QQ factor brace 2
FXX
Axial force
MIP
In-plane bending force
MOP
Out-of-plane bending force
AL.FXXB1
Allowable axial force brace 1
AL.MIPB1
Allowable in-plane bending force brace 1
AL.MOPB1
Allowable out-of-plane bending force brace 1
AL.FXXB2
Allowable axial force brace 2
AL.MIPB2
Allowable in-plane bending force brace 2
AL.MOPB2
Allowable out-of-plane bending force brace 2
UC.AXIAL
Axial unity check
UC.IP
In-plane bending unity check
UC.OP
Out-of-plane bending unity check
UC.BEND
Bending unity check
UC.AX+BN
Combined axial + bending unity check
UC.JOIN
Joint strength unity check
2.8.3.9. API LRFD Joint Checks
Characters 17-20 of the results type for joint checks are always ^^UC.
The API JOIN results components are tabulated below; only tubular sections can be subject to joint
checks. Only LRFD checks are valid; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE1
Joint 1 type
JT.TYPE2
Joint 2 type
MESSAGE1
Message 1 *
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RESULTS COMPONENT
DESCRIPTION
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
PROP.JT1
Proportion of joint 1
PROP.JT2
Proportion of joint 2
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
GAP
Gap
BRAC.DIA
Brace diameter
BRAC.THK
Brace thickness
BETA
Beta factor
TAU
Tau factor
THETA
Theta
SAXCH
Chord stress
YIELDCH
Chord yield stress
YIELDBR
Brace yield stress
SAXBR
Brace axial stress
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
QF.AXIAL
Axial QF factor
QF.IPLAN
In-plane QF factor
QF.OPLAN
Out-of-plane QF factor
QU.AX1
Axial QU factor brace 1
QU.IP1
In-plane bending QU factor brace 1
QU.OP1
Out-of-plane bending QU factor brace 1
QU.AX2
Axial QU factor brace 2
QU.IP2
In-plane bending QU factor brace 2
QU.OP2
Out-of-plane bending QU factor brace 2
FXX
Axial force
MIP
In-plane bending force
MOP
Out-of-plane bending force
AL.FXXB1
Allowable axial force brace 1
AL.MIPB1
Allowable in-plane bending force brace 1
AL.MOPB1
Allowable out-of-plane bending force brace 1
AL.FXXB2
Allowable axial force brace 2
AL.MIPB2
Allowable in-plane bending force brace 2
AL.MOPB2
Allowable out-of-plane bending force brace 2
CHOR.LEN
Chord effective length
CHOR.NOM
Chord nominal thickness
34
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Obtaining Results
RESULTS COMPONENT
DESCRIPTION
AL.FXC
Allowable cross chord force
UC.AXIAL
Axial unity check
UC.IP
In-plane bending unity check
UC.OP
Out-of-plane bending unity check
UC.XCH
Load transfer across chord unity check
UC.AX+BN
Combined axial + bending unity check
UC.JOIN
Joint strength unity check
2.8.3.10. BS5950 Member Checks
Characters 17-20 of the results type for BS5950 member unity checks are ^^UC for local member results,
UCOV for overall member results.
The results components are as tabulated below; components marked * are stored as character strings.
Local member results:
RESULTS COMPONENT
DESCRIPTION
NO.SECS
No. of sections
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
FAIL
Failure flag
SEC.POSN
Section position
AL.FXX
Axial force capacity
AL.FQMJ
Major axis shear force capacity
AL.FQMN
Minor axis shear force capacity
AL.MMJ
Major axis bending moment capacity
AL.MMN
Minor axis bending moment capacity
AL.RMMJ
Reduced moment capacity, major axis
AL.RMMN
Reduced moment capacity, minor axis
UC.BN_MJ
Major axis bending unity check
UC.BN_MN
Minor axis bending unity check
UC.SH_MJ
Major axis shear unity check
UC.SH_MN
Minor axis shear unity check
UC.TENS
Axial tension unity check
UC.AX+BN
Combined axial + moment unity check
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Overall member results:
RESULTS COMPONENT
DESCRIPTION
FAIL
Failure flag
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
AL.FXXMN
Member compressive capacity – minor axis buckling
AL.FXXMJ
Member compressive capacity – major axis buckling
AL.FXXLT
Member moment capacity, lateral torsional buckling
UC.BUC_Y
Minor axis buckling unity check
UC.BUC_Z
Major axis buckling unity check
UC.LTB
Lateral torsional buckling unity check
UC.BUCKL
Overall buckling unity check
2.8.3.11. DS449 Member Checks
Characters 17-20 of the results type for DS449 member unity checks are ^^UC for local member results,
UCOV for overall member results.
The results components are as tabulated below; components marked * are stored as character strings.
If hydrostatic checks have been carried out then some additional results are stored; these are marked
(H).
Local member results:
RESULTS COMPONENT
DESCRIPTION
NO.SECS
No. of sections
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
FAIL
Failure flag
SEC.POSN
Section position
VON.MISE
Von Mises stress
SHP
Hoop stress (H)
HYD.PRES
Hydrostatic pressure (H)
REL.SR_L
Relative slenderness ratio for local buckling
AL.SAXLB
Critical stress for local buckling
AL.SHY
Critical stress for hydrostatic overpressure (H)
AL.SCR
Critical stress for combined case (H)
AL.PRES
Critical pressure (H)
UC.YIELD
Von Mises unity check
36
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RESULTS COMPONENT
DESCRIPTION
UC.SHEAR
Shear unity check
UC.BUCKL
Local buckling unity check
UC.HYDOV
Hydrostatic overpressure unity check (H)
UC.COMB
Combined local and hydrostatic unity check (H)
Overall member results:
RESULTS COMPONENT
DESCRIPTION
FAIL
Failure flag
FLAG.F_Y
Total failure flag
FLAG.F_Z
Total failure flag
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
FXX
Max axial force
MYYEQ
Y equivalent design moment
MZZEQ
Z equivalent design moment
FEULY
Y Euler buckling force
FEULZ
Z Euler buckling force
REL.SR_Y
Y relative slenderness ratio
REL.SR_Z
Z relative slenderness ratio
E.IMPE_Y
Y equivalent geometric/material imperfections
E.IMPE_Z
Z equivalent geometric/material imperfections
AL.SAX
Critical stress
UC.BUC_Y
Y total buckle unity check
UC.BUC_Z
Z total buckle unity check
2.8.3.12. DS449 Joint Checks
Characters 17-20 of the results type for DS449 joint checks are ^^UC
The results components are as tabulated below; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE1
Joint 1 type
JT.TYPE2
Joint 2 type
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
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RESULTS COMPONENT
DESCRIPTION
PROP.JT1
Proportion of joint 1
PROP.JT2
Proportion of joint 2
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
GAP
Gap
BETA
Beta factor
TAU
Tau factor
THETA
Theta
GAMMA
Gamma factor
SAXCH
Chord stress
YIELDCH
Chord yield stress
AL.SVP
Chord wall shear limit
SAXBR
Brace axial stress
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
UU.AXIAL
UU axial factor
UU.IPLAN
UU in-plane factor
UU.OPLAN
UU out-of-plane factor
CRIT.AX1
CC factor for axial ten/comp brace 1
CRIT.IP1
CC factor for in-plane bending brace 1
CRIT.OP1
CC factor for out-of-plane bending brace 1
CRIT.AX2
CC factor for axial ten/comp brace 2
CRIT.IP2
CC factor for in-plane bending brace 2
CRIT.OP2
CC factor for out-of-plane bending brace 2
FXX
Axial nominal load
MIP
In-plane bending moment
MOP
Out-of-plane bending moment
AL.FXXB1
Brace 1 axial capacity
AL.MIPB1
Brace 1 in-plane bending capacity
AL.MOPB1
Brace 1 out-of-plane bending capacity
AL.FXXB2
Brace 2 axial capacity
AL.MIPB2
Brace 2 in-plane bending capacity
AL.MOPB2
Brace 2 out-of-plane bending capacity
UC.AXIAL
Axial unity check
UC.IP
In-plane bending unity check
UC.OP
Out-of-plane bending unity check
UC.BEND
Bending unity check
UC.AX+BN
Combined axial + bending unity check
38
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Obtaining Results
2.8.3.13. NPD Member Checks
Characters 13-16 of the results type for NPD member checks are ‘^^^^‘ for 1984 edition results, ED92
for 1992 edition results.
The results components are as tabulated below; components marked * are stored as character strings.
Local member results (1984 ed):
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
No. of sections
FAIL
Failure flag
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
MESSAGE4
Message 4 *(TUBE)
SEC.POSN
Section position
SAX
Axial stress
SB
Bending stress(TUBE)
SHP
Hoop stress(TUBE)
VON.MISE
Von Mises stress
SVT
Shear stress due to torsion(TUBE)
SVB
Shear stress due to bending(TUBE)
SLR.AXL
Relative slenderness ratio (axial) (TUBE)
SLR.BEND
Relative slenderness ratio (bending) (TUBE)
SLR.HYDR
Relative slenderness ratio (lateral pressure) (TUBE)
SLR.SHR
Relative slenderness ratio (shear) (TUBE)
AL.SAX
Critical buckling stress (axial) (TUBE)
AL.SB
Critical buckling stress (bending) (TUBE)
AL.SHP
Critical buckling stress (lateral pressure) (TUBE)
AL.SV
Critical buckling stress (shear) (TUBE)
UC.AXIAL
Axial UC
UC.BEND
Bending unity check (TUBE)
UC.HYDR
Lateral pressure unity check (TUBE)
UC.TORSN
Torsional shear unity check (TUBE)
UC.SHEAR
Bending shear unity check (TUBE)
UC.YIELD
Von Mises UC
UC.AX+BN
Axial + bending combined unity check (TUBE)
UC.AX+HY
Axial + lateral pressure unity check (TUBE)
UC.AX+T
Axial + torsion unity check (TUBE)
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RESULTS COMPONENT
DESCRIPTION
UC.AX+SH
Axial + bending shear unity check (TUBE)
SVY
Max. Y shear stress (BEAM)
SVZ
Max. Z shear stress (BEAM)
UC.SHR_Y
Y shear unity check (BEAM)
UC.SHR_Z
Z shear unity check (BEAM)
Overall member results (1984 ed):
Columns 17-20 of the result type are UCOV.
RESULTS COMPONENT
DESCRIPTION
FAIL
Failure flag
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
MYYEQ
Y equivalent moment
MZZEQ
Z equivalent moment
REL.SR_Y
Y relative slenderness ratio
REL.SR_Z
Z relative slenderness ratio
FK/FY_Y
FKY to yield stress ratio
FK/FY_Z
FKZ to yield stress ratio
FTBUCY
Y theoretical buckling load
FTBUCZ
Z theoretical buckling load
FEULY
Y Euler buckling load
FEULZ
Z Euler buckling load
AL.MYY
Y ultimate bending capacity
AL.MZZ
Z ultimate bending capacity
NTD
Critical torsional axial stress
MVD
Revised buckling strength
UC.TOT_Y
Y total unity check
UC.TOT_Z
Z total unity check
Local member results (1992 ed):
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
No. of sections
FAIL
Failure flag
40
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RESULTS COMPONENT
DESCRIPTION
MESSAGE2
Message 2 *
MESSAGE4
Message 4 *
SEC.POSN
Section position
SAX
Axial stress
SB
Bending stress
SHP
Hoop stress
VON.MISE
Von Mises stress
SVT
Torsional stress
SVB
Max. bending shear stress
UC.YIELD
Von Mises (Yield) unity check
Overall member results (1992 ed):
Columns 17-20 of the result type are UCOV.
RESULTS COMPONENT
DESCRIPTION
FAIL
Failure flag
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
MYYEQ
Y equivalent moment
MZZWQ
Z equivalent moment
UC.TOT_Y
Y total unity check
UC.TOT_Z
Z total unity check
2.8.3.14. NPD Joint Checks
Characters 13-16 of the results type for NPD joint checks are ‘^^^^‘ for 1984 edition results, ED92 for
1992 edition results.
The results components are as tabulated below; components marked * are stored as character strings.
Local member results (1984 ed):
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE
Joint 1 type
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
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RESULTS COMPONENT
DESCRIPTION
MESSAGE3
Message 3 *
THETA
Theta
BETA
Beta
TAU
Tau
GAMMA
Gamma
JT.GOM.F
Joint geometry factor
ST.CHO.F
Chord stress factor
SAXBR
Brace axial stress
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
SAXCH
Chord axial stress
SBCH
Chord bending stress
YIELDCH
Chord shear yield stress
SVP
Acting punching shear
AL.SVP
Critical joint punching shear stress
UC.PUNCH
Punching unity check
UC.YIELD
Yield unity check
Local member results (1992 ed):
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
JT.TYPE
Joint 1 type
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
THETA
Theta
BETA
Beta
GAMMA
Gamma
SAXBR
Brace axial stress
SIPBR
Brace in-plane stress
SOPBR
Brace out-of-plane stress
SAXCH
Chord axial stress
SBYCH
Chord y bending stress
SBZCH
Chord z bending stress
UC.AXIAL
Axial unity check
42
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RESULTS COMPONENT
DESCRIPTION
UC.IP
In-plane unity check
UC.OP
Out-of-plane unity check
UC.AX+BN
Combined unity check
2.8.3.15. NORSOK Member Checks
The results components for NORSOK member checks are as tabulated below; components marked *
are stored as character strings.
Characters 17-20 of the results type for member unity checks are always ^^UC.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
T/C
Tension / compression indicator *
CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
SEC.POSN
Section position
CMY
Y moment amplification reduction factor
CMZ
Z moment amplification reduction factor
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
LAMBDA
Column slenderness parameter
AL.SAX
Allowable axial stress
AL.SV
Allowable shear stress
AL.SVT
Allowable torsion stress
AL.SB
Allowable bending stress
AL.SEULY
Allowable Y Euler buckling stress
AL.SEULZ
Allowable Z Euler buckling stress
YIELD
Allowable Yield
UC.AXIAL
Axial unity check
UC.SHEAR
Shear unity check
UC.TORSN
Torsion unity check
UC.BND_Y
Y Bending unity check
UC.BND_Z
Z Bending unity check
UC.BEND
Resultant Bending unity check
UC.SH+BN
Bending + shear unity check
UC.S+B+T
Shear, bending and torsion unity check
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RESULTS COMPONENT
DESCRIPTION
UC.YLD1
Yield1 unity check
UC.YLD2
Yield2 unity check
2.8.3.16. NORSOK HYDR Checks
The results components for NORSOK hydrostatic checks are as tabulated below; components marked
* are stored as character strings.
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
SEC.POSN
Section position
HYD.DPTH
Hydrostatic depth
GOMPAR.M
Geometry parameter
HBUC.COF
Hoop buckling coefficient
SHP
Hoop stress
AL.SAX
Allowable axial stress
AL.SB
Allowable bending stress
AL.SAX_E
Allowable elastic axial stress
AL.SAX_I
Allowable inelastic axial stress
AL.SHP_E
Allowable elastic hoop stress
AL.SHP_I
Allowable inelastic hoop stress
UC.HOOPC
Hoop compressive unity check
UC.C1
Combined hoop and axial unity check
UC.C2
Combined hoop bending and axial 1 unity check
UC.C3
Combined hoop bending and axial 2 unity check
UC.COMB
Combined unity check
2.8.3.17. NORSOK Joint Checks
The results components for NORSOK joint checks are as tabulated below; components marked * are
stored as character strings.
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
CHORD
Chord number
44
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RESULTS COMPONENT
DESCRIPTION
JT.TYPE1
Joint 1 type *
JT.TYPE2
Joint 2 type *
LD.CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
PROP.JT1
Proportion of joint 1
PROP.JT2
Proportion of joint 2
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
GAP
Gap
BRAC.DIA
Brace diameter
BRAC.THK
Brace thickness
BETA
Beta factor
TAU
Tau factor
THETA
Theta
SAXCH
Chord stress
YIELDCH
Chord yield stress
YIELDBR
Brace yield stress
SAXBR
Brace axial stress
SIPBR
Brace in-plane bending stress
SOPBR
Brace out-of-plane bending stress
QF.AXIAL
Axial QF factor
QF.IPLAN
In-plane bending QF factor
QF.OPLAN
Out-of-plane bending QF factor
QU.AX1
Axial QU factor brace 1
QU.IP1
In-plane bending QU factor brace 1
QU.OP1
Out-of-plane bending QU factor brace 1
QU.AX2
Axial QU factor brace 2
QU.IP2
In-plane bending QU factor brace 2
QU.OP2
Out-of-plane bending QU factor brace 2
FXX
Axial force
MIP
In-plane bending force
MOP
Out-of-plane bending force
AL.FXXB1
Allowable axial force brace 1
AL.MIPB1
Allowable in-plane bending moment brace 1
AL.MOPB1
Allowable out-of-plane bending moment brace 1
AL.FXXB2
Allowable axial force brace 2
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RESULTS COMPONENT
DESCRIPTION
AL.MIPB2
Allowable in-plane bending moment brace 2
AL.MOPB2
Allowable out-of-plane bending moment brace 2
CHOR.LEN
Chord effective length
CHOR.NOM
Chord nominal thickness
UC.AXIAL
Axial unity check
UC.IP
In-plane bending unity check
UC.OP
Out-of-plane bending unity check
UC.AX+BN
Combined axial + bending unity check
2.8.3.18. ISO Member Checks
The results components for ISO member checks are as tabulated below; components marked * are
stored as character strings.
Characters 17-20 of the results type for member unity checks are always ^^UC.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
T/C
Tension / compression indicator *
CODE
Alpha codes *
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
MESSAGE3
Message 3 *
MESSAGE4
Message 4 *
SEC.POSN
Section position
CMY
Y moment amplification reduction factor
CMZ
Z moment amplification reduction factor
LAMBDA
Column slenderness parameter
AL.SAX
Allowable axial stress
AL.SV
Allowable shear stress
AL.SVT
Allowable torsion stress
AL.SBY
Allowable Y bending stress
AL.SBZ
Allowable Z bending stress
AL.SEULY
Allowable Y Euler buckling stress
AL.SEULZ
Allowable Z Euler buckling stress
AL.SAXLB
Allowable local buckling stress
UC.AXIAL
Axial unity check
UC.SHEAR
Shear unity check
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Obtaining Results
RESULTS COMPONENT
DESCRIPTION
UC.TORSN
Torsion unity check
UC.BND_Y
Y Bending unity check
UC.BND_Z
Z Bending unity check
UC.BEND
Resultant Bending unity check
UC.YLD1
Yield1 unity check
UC.YLD2
Yield2 unity check
2.8.3.19. ISO HYDR Checks
The results components for ISO hydrostatic checks are as tabulated below; components marked * are
stored as character strings.
Columns 17-20 of the result type are ^^UC.
RESULTS COMPONENT
DESCRIPTION
NO.SECS
Number of sections
FAIL
Failure flag (1=fail)
MESSAGE1
Message 1 *
MESSAGE2
Message 2 *
SEC.POSN
Section position
HYD.DPTH
Hydrostatic depth
GAMMAD
Hydrostatic load factor
GOMPAR.M
Geometry parameter
HBUC.COF
Hoop buckling coefficient
SHP
Hoop stress
AL.SAX
Allowable axial stress
AL.SB
Allowable bending stress
AL.SAX_E
Allowable elastic axial stress
AL.SAX_I
Allowable inelastic axial stress
AL.SHP_E
Allowable elastic hoop stress
AL.SHP_I
Allowable inelastic hoop stress
UC.HOOPC
Hoop compressive unity check
UC.C1
Combined hoop and axial unity check
UC.C2
Combined hoop bending and axial 1 unity check
UC.C3
Combined hoop bending and axial 2 unity check
UC.COMB
Combined unity check
2.8.3.20. ISO Joint Checks
Characters 17-20 of the results type for joint checks are always ^^UC.
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Facilities in BEAMST
The ISO JOIN check results components are tabulated below; only tubular sections can be subject to
joint checks; components marked * are stored as character strings.
RESULTS COMPONENT
DESCRIPTION
MESSAGE1
Messages *
MESSAGE2
Messages *
MESSAGE3
Messages *
AL.PA
Allowable Pa
AL.MAIP
Allowable Ma i/plane
AL.MAOP
Allowable Ma o/plane
BETA
Beta factor
GAMMA
Gamma ratio
TAU
Tau ratio
THETA
Theta angle
CHORD
1st chord member
CHOR.PC
Chord axial force
CHOR.MIP
Chord Moment i/plane
CHOR.MOP
Chord moment o/plane
CHOR.MP
Chord capacity
CHOR.PY
Chord strength
CHOR.DIA
Chord diameter
CHOR.THK
Chord thickness
FXX
Brace axial force
MIP
Brace Moment i/plane
MOP
Brace Moment o/plane
BRAC.DIA
Brace Diameter
BRAC.THK
Brace Thickness
SPEC.CSE
Spectral Loadcase expansion code *
The components for each joint type assessment for axial loading are as
follows. For joint types 2 – 5 just replace the digit at the end of the component name
Components
for joint type 1
JT.TYPE1
Joint type (Y/K/X) *
PROP.JT1
Joint proportion (%)
BAL.JT1
Balancing member no. (not applicable for Y joints)
QU.AX1
Axial Qu factor
QF.AX1
Axial Qf factor
GAP.JT1
Gap factor. The gap factor value depends on the joint type, the result
is as follows:
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Obtaining Results
RESULTS COMPONENT
DESCRIPTION
X joints – Qb value for brace in compression, e/D ratio for brace in
tension
K joints – gap value
Y joints – Not applicable
Components
for bending
results
QU.IP
Qu factor, in plane
QU.OP
Qu factor, out of plane
QF.IPLAN
Qf factor, in plane
QF.OPLAN
Qf factor, out of plane
Unity check results
UC.AXIAL
Axial capacity unity check
UC.IP
Bending in plane capacity unity check
UC.OP
Bending out of plane capacity unity check
UC.AX+BN
Combined forces capacity unity check
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49
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Chapter 3: BEAMST Command Reference
The input of information and data is divided into two sections. The first is the Preliminary Data followed
by the main BEAMST Data.
The Preliminary Data defines the information required for the analysis whereas the Main Data defines
the code check specific information.
3.1. BEAMST Command Structures
BEAMST has the following command structures:
3.1.1. BEAMST Command Syntax
3.1.2. BEAMST Command Data Types
3.1.3. BEAMST Command Special Symbols
3.1.4. BEAMST NOT Command Modifier
3.1.1. BEAMST Command Syntax
Each command consists of a command word followed by a number of parameters and, where applicable,
an assignment list to which the parameters are attributed. This is shown diagramatically as follows:
Within each command line, each horizontal branch represents a possible input instruction. Input instructions are composed of keywords (shown in UPPER-CASE characters), numerical values or alphanumerics
(shown in lower-case characters) and special symbols (see BEAMST Command Data Types (p. 52) and
BEAMST Command Special Symbols (p. 53)). Each item in the list is separated from each other by a
comma or one or more blank spaces.
Only the first four characters of a command are interpreted. Thus the following commands will produce
the same results.
EFFE 2.0 ELEM ALL
EFFECTIVE_LENGTH 2.0 ELEM ALL
EFFECTIVE 2.0 ELEM ALL
Some data lines require an integer or real list to be input where length is variable. This is shown by a
horizontal arrow around the list variable:
Optional data items are indicated by an arrow which bypasses the item(s):
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BEAMST Command Reference
Alternatively, where optional items are part of a list of values they may be represented by enclosing
brackets:
Where one or more possible alternative items may appear in the line, these are shown by separate
branches for each. These branches may rejoin further along the command if appropriate:
An input line must not be longer than 80 characters.
3.1.2. BEAMST Command Data Types
Data is entered in three forms:
a. Integer Number and Lists
If an integer number is required a decimal point must not be supplied. When a list of integer
numbers is required, the following abbreviations may be used:
i.
Where the integer list represents all items from an existing list (for example, choosing all elements
for processing) the list may be replaced by the word ALL. For example:
ELEM ALL selects all possible elements.
ii. A sequence of integers may be generated by giving the first and last values separated by the
keyword TO. For example 5 TO 8 generates the numbers 5,6,7 and 8.
b. Real Number
If a real number is required the decimal point may be omitted if the value is a whole number.
Exponent formats may be utilized when real numbers are required. For example, the following
are equivalent:
0.004
4.0E-3
4.0D-3
Similarly, the following have the same value:
410.0
410
4.10E2
c. Alphanumeric
Alphanumeric data is used for keywords and text strings. Alphanumerics are any non-numeric
strings which may include the letters A-Z, numbers 0-9, and the characters +, -, / and :. The
letters A-Z may be supplied in either upper or lower case but no distinction is made between
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BEAMST Command Structures
the upper and lower case form. Hence “A” is assumed identical with “a”, “B” with “b” and so
on. For example:
COMB
Comb
comb
are all identical strings.
Alphanumeric strings must not include any special symbols (see BEAMST Command Special
Symbols (p. 53)).
3.1.3. BEAMST Command Special Symbols
The following is a list of characters that have a special significance to the BEAMST input:
*
An asterisk is used to define the beginning of a comment, whatever follows on the
line will not be interpreted. It may appear anywhere on the line, any preceding data
will be processed as normal. For example:
* THIS IS A COMMENT FOR THE WHOLE LINE
CASE 4 2.7 * THIS IS A COMMENT FOR PART OF A LINE
,
A comma or one or more consecutive blanks will act as a delimiter between items
in the line.
For example:
5, 10, 15
is the same as
5 10 15
Note that two commas together signify that an item has been omitted. This may
be permissible for certain data blocks.
For example: 5,, 15 is the same as 5 0 15
Unless otherwise stated in the section describing the data block, omitted numerical values are zero.
:
A colon at the start of the line signifies that the line is a continuation from the previous line.
For example
5
: 10
: 15
is the same as
5 10 15
@
A command @filename may appear anywhere in a data file. When such a command
is encountered, the input of data switches to the file filename and data continues to
be read from that file until either the end-of-file is reached or an @ command is encountered in the secondary file.
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BEAMST Command Reference
When the end of the secondary file is reached, that file is closed and input
switches back to the previous data file. If, however, an @ command is found in
the secondary file, input switches to yet another file. This process can continue
until a maximum of 5 secondary files are open simultaneously.
For example
@prelim.dat
@prelim.dat
@select.dat
@geom.dat
@load.dat
geom.dat might then contain the lines
@desi.dat
@effe.dat
@unbr.dat
@cm.dat
finally
desi.dat contains the DESI commands
effe.dat contains the EFFE commands
etc.
3.1.4. BEAMST NOT Command Modifier
The NOT command modifier may be used with ELEM and JOIN commands to switch off items previously
selected for processing. A typical use of the NOT command modifier is when all but a few elements
from a large group are to be processed. The elements may be selected first using the ALL option, and
then the unwanted elements deselected using the NOT ELEM command. The order in which selections
are made is important as the final setting for a particular element determines whether that element is
processed. Elements may be switched ‘on’ and ‘off’ repeatedly as in the example below:
ELEM ALL
NOT ELEM 1 TO 60
ELEM 8 TO 16
NOT ELEM 13
If the model contains elements 1 to 100, then the above commands select elements:
8 9 10 11 12 14 15 16 and 61 to 100
In the special case where the NOT ELEM command is the first to appear in the data it has the effect of
switching ‘on’ all elements apart from those specified on the command.
The NOT JOIN command operates in a similar fashion to the NOT ELEM command.
3.2. BEAMST Command Sets
BEAMST data is grouped into command sets according to the requirements of each type of code check.
Each command set consists of a header command for the code check, the commands applicable to the
check and an END command to terminate the set. It is permissible to run several different code checks
by appending the command sets in a single BEAMST datafile. It should be noted however that if plot
files are to be saved then command sets should not be appended.
The structure of a typical BEAMST datafile for multiple check types is shown below:
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BEAMST Command Sets
The header command for each command set consists of a keyword defining the design code, a second
keyword (or sub-header) defining the particular requirements from the code and in some instances
further keywords defining editions, amendments and check classes.
The preliminary data is the first block of the BEAMST data. It defines the memory size to be used, the
project name, structure and component names, file names and options to be used. It also defines which
files are to be saved for further processing.
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BEAMST Command Reference
The preliminary data must contain at least a JOB, STRUCTURE, ANSYS, and END command for Mechanical APDL analyses. Other commands should be used as appropriate.
The BEAMST command sets are summarized in the table below. The commands relevant to each command set are summarized in the tables that follow, the reference for each is also given in the table
below.
3.3. BEAMST Priority of Data Assignments
There are a number of commands that allow element and element ‘step’ data to be assigned in terms
of element, group (Asas analysis only), or property numbers. These appear in the command syntax
diagrams in the following format:
The priority of such assignments is defined below:
Element data - use element data assigned to individual elements (ELEM)
if none - use element data assigned to the group the element belongs to (GROU)
if none - use element data assigned to the property integer used by the element (PROP or MATE)
if none - no element data assigned to element.
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ABNO
Step data - use step data assigned to individual elements (ELEM)
if none - use step data assigned to the group the element belongs to (GROU)
if none - use step data assigned to the property integer used by the element (PROP or MATE)
if none - use element data assigned to individual elements (ELEM)
if none - use element data assigned to the group the element belongs to (GROU)
if none - use element data assigned to the property integer used by the element (PROP or MATE)
if none - no step data assigned to element.
Element and step data assignment is not order dependant. This is demonstrated by the following example:
COMMand
COMMand
COMMand
COMMand
....
....
....
....
data1
data2
data3
data4
ELEM
GROU
ELEM
PROP
1
5
2
1
Assuming elements 1 and 2 are in group 5:
Element 1 has data1 assigned
Element 2 has data3 assigned
All other elements in group 5 have data 2 assigned
All elements with property integer 1, except elements 1 and 2 and elements in group 5, have data4
assigned.
It should be noted that when step data is explicitly being defined it overrides any element assignments
even if the step data is assigned to a group or property and the element data assigned to an individual
element. Thus in the following example:
COMMand
COMMand
COMMand
COMMand
....
....
....
....
data1
data2
data3
data4
STEP
STEP
ELEM
STEP
2 GROU 5
2 PROP 1
1
2 ELEM 2
Step 2 of element 1 has data1 assigned because the group assignment overrides the property assignment.
In this instance the step specific group assignment also overrides the element assignment which is not
step specific.
Step 2 of element 2 has data4 assigned.
Step 2 of all other elements in group 5 have data1 assigned.
Step 2 of all elements with property integer 1, except those in group 5, have data2 assigned.
All steps, except step 2, of element 1 have data3 assigned.
No data is assigned to any steps, other than step 2, for any elements other than element 1.
3.4. ABNO
The ABNORMAL command is used to specify which basic and/or combined loadcases are to utilize
improved resistance factors for structures subjected to abnormal loading conditions, typically those
required for progressive collapse analyses.
Parameters
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BEAMST Command Reference
ABNO
Keyword
load list
List of basic and/or combined user loadcase numbers (Integer).
Usage
Optional, applicable to API LRFD and ISO code checks only.
Notes
1. All user loadcase numbers must be explicitly defined, no shorthand syntax is permissible.
2. For loadcases defined as abnormal, all resistance factors utilized will be set to unity. The resistance factors
and their default values for API LRFD check are given below:
Factor
Default
Value
φc - resistance factor for axial compressive
strength
0.85
φt - resistance factor for axial tensile strength
0.95
φh - resistance factor for hoop buckling
strength
0.80
φv - resistance factor for beam shear strength
0.95
φb - resistance factor for bending strength
0.95
φj - resistance factor for joint connection
0.95a
φq - resistance factor for yield
0.95
a
The connection resistance factor depends upon the joint type and load component being considered. The value of 0.95 is used for
all variants except axial tension for T, Y and X joints, where a value of 0.90 is utilized.
The partial resistance factors adopted for normal load cases for the ISO check are given in BEAMST ISO
Theory (p. 435).
Examples
ABNO 2 4
3.5. AISC
The AISC header command selects stress checks to the AISC design specifications (Ref. 1 and Ref. 23).
Parameters
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ANSYS
AISC
Keyword
WSD
Selects working stress design methods.
LRFD
Selects limiting resistance and factored load design methods.
edition
Selects the edition of AISC. Valid keywords are:
• ED2 or ED3 for LRFD
• ED8 or ED9 for WSD
ALLO/MEMB
Selects member design checks.
Usage
Compulsory for all AISC checks. Must be the first command within the command data block.
Notes
1. A list of all commands applicable to the AISC command data block is given in the AISC Theory section.
2. In the absence of any sub-commands, this command defaults to AISC WSD ALLO.
3. In the absence of the edition sub-command AISC ALLO will default to the 8th edition. AISC ED9 ALLO
is required to invoke the 9th edition.
3.6. ANSYS
This command defines the name of the Mechanical APDL job from which the analysis results will be
obtained. The command is mandatory if BEAMST is to be performed following a Mechanical APDL
analysis and must be omitted otherwise.
The ANSYS command is a preliminary command, and should only appear at the head of the
BEAMST data set.
Parameters
ANSYS
Keyword
FNAME
Keyword to denote that the job names are specified in a job name list file (Optional).
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BEAMST Command Reference
Jobname
1. Without FNAME – job name of the Mechanical APDL model to be processed. This is the name associated with the .RST file generated by Mechanical APDL (Alphanumeric, up to 32 characters).
2. With FNAME – name of file containing paths and names of Mechanical APDL jobs to be included in
the analysis together.
youngs
Young's Modulus (Optional, Real).
density
Material density (Optional, Real).
Notes
1. BEAMST will only process certain Mechanical APDL beam element types in an ANSYS model. Valid element
names are:
BEAM44, BEAM188*, BEAM189*, PIPE16, PIPE59*, PIPE288*, PIPE289*
Elements marked with * must be meshed within Mechanical APDL (that is, many elements to one
member). The UNBR command should be used to define the unbraced length, otherwise incorrect
results will be obtained.
2. If youngs is omitted, the Young’s modulus of steel will be assumed, i.e. youngs = 2.1E11 N/m2. If youngs
is specified, it is assumed that the value is consistent with the units adopted in the ANSYS analysis.
3. If density is omitted, the density of steel will be assumed, i.e. density = 7850 kg/m3. If density is specified,
it is assumed that the value is consistent with the units adopted in the ANSYS analysis.
4. The job name list file specified after keyword FNAME consists of a number of data lines that define the
Mechanical APDL results sets (i.e. load cases) to be analyzed by BEAMST. The format of each data line is
described as follows:
FullPathName (LCAnsys) (LCAsas)
where
FullPathName is the name of the .RST file including path if necessary. If no path is specified, it is
assumed that the .RST file is located in the same directory as the BEAMST data file. If the specified
string contains any embedded space, then the whole string must be bounded by double quotes (“).
LCAnsys is the system result set number in the .RST file where results will be considered in BEAMST.
If it is zero or not specified, all result sets in the .RST file will be transferred to BEAMST.
LCAsas is the ASAS user load case number for this Mechanical APDL result set in BEAMST. If it is
zero or not specified, it will be set as the last assigned BEAMST user load case number + 1. If multiple
Mechanical APDL result sets are implied in the command (i.e. LCAnsys = 0), LCAsas defines the user
load case number of the first
5. If the Mechanical APDL job name is specified directly (i.e. without FNAME), all the Mechanical APDL
results sets in the .RST file will be transferred to BEAMST with user load case numbers ranging from 1 to
the number of result sets.
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API
6. If the BEAMST load cases care are obtained from multiple Mechanical APDL analyses, user must ensure
that all the models are consistent as no cross checks will be carried out by BEAMST.
Examples
1. The Mechanical APDL analysis is a single job called ANSYSJOB. All the load cases in this job will be analyzed
in BEAMST.
ANSYS ANSYSJOB
2. The Mechanical APDL analysis information is contained in a job name file called Ansysfile.txt, which references three Mechanical APDL jobs called Ansysjob1, Ansysjob2 and Ansysjob3 located in different
directories. The first load case (results set) in each of these 3 jobs will become load cases 10, 20 and 30
in BEAMST.
ANSYS FNAME Ansysfile.txt
The contents of file Ansysfile.txt are:
C:\AnsysAnalysis\Job1\Ansysjob1 1 10
“C:\AnsysAnalysis\Job2\Ansysjob2” 1 20
C:\AnsysAnalysis\Job3\Ansysjob3 1 30
3.7. API
The API command selects stress checks to the API design recommendations.
Parameters
API
Keyword
WSD
Selects working stress design methods.
LRFD
Selects limiting resistance and factored load design methods.
edition
Selects the edition of API. Valid keywords are:
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BEAMST Command Reference
• ED1 for LRFD
• ED13, ED16, ED17, ED18, ED19, ED20, or ED21 for WSD.
ALLO/MEMB
Selects member design checks.
HYDR
Selects hydrostatic collapse check for tubulars.
NOMI
Selects joint nominal load check for tubulars (not valid with ED13) to WSD.
PUNC
Selects joint punching shear check for tubulars to WSD.
JOIN
Selects joint check for tubulars to LRFD. or WSD ED21
Usage
Compulsory for all API checks. Must be the first command within the command data block.
Notes
1. When BEAMST is run in stand-alone mode, the program can be used for member checks only and so
commands NOMI, PUNC and JOIN are not allowed.
2. A list of all commands applicable to the API Command data block is given in the API Theory section.
3. If the design method is omitted WSD is assumed.
4. The edition of API must be specified using one of the valid keywords listed above.
5. If the sub-command defining the check type is omitted (MEMB, ALLO etc) the check defaults to ALLO
for WSD, and MEMB for LRFD.
6. ALLO checks tubular members to API WSD recommendations and non-tubular members to AISC as referred
to in the API recommendations (See the BEAMST API Theory section ).
7. MEMB, HYDR, JOIN, NOMI and PUNC check tubular members only to API recommendations. NOMI/PUNC
options are not valid for the API WSD ED21; JOIN should be used instead. The JOIN option is not valid
for editions prior to ED21”.
3.8. BRIG
The BRIG command selects whether rigorous buoyancy should or should not be used in the hydrostatic
member checks.
Parameters
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CASE
BRIG
Keyword
ON
Selects rigorous buoyancy for this command deck.
OFF
De-selects buoyancy for this command deck.
Usage
Optional. If omitted all hydrostatic code checks will NOT consider the effects of rigorous buoyancy.
Notes
1. The application of this command should be compatible to the application of the ocean loading in
Mechanical APDL or Asas WAVE.
3.9. BS59
The BS59 command selects ultimate limit state checks to BS5950 (Ref. 4).
Parameters
BS59
Keyword
MEMB
Selects member stress checks to BS5950.
Usage
Compulsory for all BS5950 checks. This must be the first command within the BS59 Command data
block.
Notes
1. A list of all commands applicable to the BS59 Command data block is given in the BS5950 Theory section.
2. In the absence of a sub-command, keyword defaults to MEMB
3.10. CASE
The CASE command is used to specify which basic loadcases from the previous analysis are to be reported.
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BEAMST Command Reference
Parameters
CASE
Keyword
integer list
List of basic loadcases to be reported (Integer).
Usage
Optional for all command data blocks. At least one CASE, CMBV or COMB command must be present
in each command data block.
Notes
1. All basic (CASE) loadcase numbers and all combined (COMB and CMBV) loadcase numbers selected for
reporting must be unique.
Examples
CASE 1 3 5
CASE ALL
3.11. CB
The CB command specifies a default value of the pure bending coefficient, Cb to be used for selected
elements.
Parameters
CB
Keyword
value
Pure bending coefficient (Real).
ELEM
Keyword to denote element list follows:
integer list
List of basic loadcases to be reported (Integer).
Usage
Optional - applicable to AISC/API ALLO Command data blocks only.
Notes
1. If omitted the program will calculate a Cb value based on the acting force distribution on each member.
See the BEAMST AISC Theory section.
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CHOR
If a member is modeled by more than one element, the force distribution along the member will
only be determined from the results at the ends of the constitutive elements forming the member.
All element interior positions specified by the SEAR or SECT commands will be ignored.
Examples
CB 1.0 ELEM 5 77 TO 100 742
CB 2.0 ELEM 973
3.12. CHOR
The CHOR command is used to define the chord member(s) at a node and optional chord parameters.
Parameters
CHOR
Keyword
node
Node number (Integer).
ELEM
Keyword to denote element list follows:
member1
User element number(s) defining chord member(s) (Integer).
member2
User element number(s) defining chord member(s) (Integer).
EFFE
Keyword to denote chord parameters follow:
thick
Chord nominal thickness away from the joint (Real).
length
Chord effective length (Real).
LTOD
Keyword to denote length to diameter ratio follows.
ratio
Maximum chord length between nodes to be used when forming a multi-noded joint; given as ratio
of length over diameter (Real).
Usage
Optional for tubular joint punching shear and nominal load joint checks. The chord parameters are
currently ONLY used by the API LRFD nominal load joint check and the API WSD JOIN check.
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Notes
1. For single noded joints the node number is the same as the joint number, for multiple noded joints the
CHOR command can be used for one or more nodes forming the joints.
2. In the absence of any CHOR command(s) pertaining to a node, the chord will be identified as that
member at the joint with the greatest diameter. If several members have the same diameter, BEAMST
will check their wall thickness and choose the most appropriate member for API WSD JOIN checks. The
member length will also be considered as nodes within the ratio specified, this defaults to 0.25 (D/4)
and the chords will be connected to form a multi-noded joint.
3. In the API LRFD nominal load joint check, cross joints should be checked for chord crushing if the chord
is reinforced only by a can having increased thickness local to the joint. To undertake this check an effective chord length and nominal thickness must be provided using this command.
4. In the API WSD JOIN check clause 4.3.5 for thickened cans will only be invoked if chord parameters are
provided.
Examples
CHORD
CHORD
CHORD
CHORD
16
16
16
16
122
120 122
ELEM 122
EFFE 20.0 1500.0
3.13. CMBV
The CMBV command is used to select a new combined loadcase to be reported and to specify the
loadcase numbers and factors to be combined into the new loadcase. It differs from the COMB command
in that the combination may be carried out in several different ways. Combinations which include other
combinations are permissible.
Parameters
CMBV
Keyword
ctype
Describes the combination method (see Note 2).
newcase
Combined loadcase number (Integer).
factor
Multiplicative factor to be applied to case (Real).
case
User loadcase number, either a basic loadcase or another combination loadcase number (Integer).
Usage
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CMY/CMZ
Optional for all command data blocks. At least one CASE, CMBV or COMB command must be present
in each command data block.
Notes
1. All basic (CASE) loadcase numbers and all combined (CMBV and COMB) loadcase numbers selected for
reporting must be unique.
2. Five combination types are permitted using the CMBV command:
SSUM
Simple summation. The factored forces and moments for each of the constituent loadcases are simply
added together.
MAXE
Maximum envelope. The factored forces and moments for each of the constituent loadcases are
considered in turn. The final results consist of the highest (positive) force values found in the constituent loadcases for each force type.
MINE
Minimum envelope. The factored forces and moments for each of the constituent loadcases are
considered in turn. The final results consist of the lowest (negative) force values found in the constituent loadcases for each force type.
ABSS
Absolute sum. The absolute values of the factored forces and moments for each of the constituent
loadcases are added together. All resulting forces and moments will be positive.
SRSS
Square root sum square. The factored forces and moments for each of the constituent loadcases are
squared and then added together. The resulting forces are then square rooted. All resulting forces
will be positive. This is useful for combining spectral loadcases.
3. For combinations other than SSUM care must be exercised in the processing of these results because
they do not necessarily represent a consistent set of fixed end forces and distributed loads.
4. Loadcase combination is generally invalid in a non-linear analysis.
Examples
CMBV SSUM 10 1.5 14 2.0 101
CMBV ABSS 303 1.4 6 1.6 7
3.14. CMY/CMZ
The CMY/CMZ command specifies the amplification reduction factors Cmy and Cmz to be used in the
member combined stress buckle unity check and hydrostatic collapse checks (see below for applicable
codes of practice).
Parameters
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CMY/CMZ
Keyword
value
Cmy or Cmz value (Real).
ELEM
Keyword to denote element list follows:
integer list
List of basic loadcases to be reported (Integer).
Usage
Optional - applicable to the following codes of practice only.
• ISO MEMB and ISO HYDR
• NORS MEMB and NORS HYDR
• API ALLO and API HYDR
• AISC ALLO
Notes
1. If omitted the program will calculate Cmy and Cmz values appropriate to each element based on the
acting force distribution on each member. See the AISC LRFD Theory section for calculation methodology.
2. A limiting maximum of 0.85 will be applied unless overridden by user specification using this command.
3. If a member is modeled by more than one element, the force distribution along the member will only
be determined from the results at the ends of the constitutive elements forming the member. All element
interior positions specified by the SEAR or SECT commands will be ignored.
Examples
CMY 0.85 ELEM 5 77 TO 742
CMZ 0.40 ELEM 973
3.15. COMB
The COMB command is used to select a new combined loadcase to be reported and to specify the
loadcase numbers and factors to be combined into the new loadcase. Combinations which include
other combinations are permissible.
Parameters
COMB
Keyword
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COMPONENT
factor
Multiplicative factor to be applied to case (Real).
case
User loadcase number, either a basic loadcase or another combination loadcase number (Integer).
Usage
Optional for all command data blocks. At least one CASE, CMBV or COMB command must be present
in each command data block.
Notes
1. All basic (CASE) loadcases and all combined (CMBV and COMB) loadcase numbers selected for reporting
must be unique.
2. Loadcase combination is generally invalid in a non-linear analysis.
Examples
COMBINE 16 0.9 14 1.2 3050
COMB 303 1.4 6 1.6 7
3.16. COMPONENT
The COMP command is used to define the recovered component from a substructure analysis for which
the results are to be processed in this run. Only applicable to an ANSYS Asas based analysis.
The COMP command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
COMP
Keyword
sname
Structure name identifying which existing structure is to be accessed from the current project. See the
PROJECT command. (Alphanumeric, 4 characters, the first character must be alphabetic).
tree
This is the path down the component tree from the given structure in sname to the component which
is being used for the BEAMST processing.
Usage
Valid only, and compulsory, for recovered components.
Notes
1. If the user is processing the global structure run in a substructure analysis, use only the STRU command.
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2. The component referred to by tree on this command must have been recovered by an ASAS stress recovery run. The ASAS run must have contained a SAVE LOCO FILES command.
Examples
To process the second level component CMP2, part of assembled component CMP1, which in turn is
part of structure STRU:
COMP STRU CMP1 CMP2
3.17. COOR
The COOR command is used to define the nodal coordinates, as printed in the member properties report.
Important
The COOR command should only be used when running BEAMST in stand-alone mode.
Parameters
COOR
Keyword
node
Node number (Integer).
x
X-coordinate of the node.
y
Y-coordinate of the node.
z
Z-coordinate of the node.
Usage
Optional for all command data blocks in stand-alone mode.
Notes
1. If the end coordinates for an element are not defined then the element will be assumed to lie along the
positive x-axis with node 1 at the origin.
2. No checks are carried out to ensure that specified coordinate data is consistent with member lengths
specified on TOPO data lines. It is essential that the user ensures that specified coordinate positions are
consistent with lengths defined in the TOPO data block.
Examples
COOR 1 10. 20. 30.
COOR 2 40. 50. 60.
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DENT
3.18. DENT
The DENT command specifies the dent depth and out-of-straightness for selected elements.
Parameters
DENT
Keyword
daxis
Keyword defining dent axis. Valid keywords are:
YPOS
dent on +ve local Y axis
YNEG
dent on -ve local Y axis
ZPOS
dent on +ve local Z axis
ZNEG
dent on -ve local Z axis
ddepth
Dent depth (Real).
dos
Maximum out-of-straightness (Real).
ELEM
Keyword to denote element list follows:
integer list
List of user element numbers (Integer).
Usage
Optional - applicable to ISO MEMB Command data blocks only.
Example
DENT YPOS 0.2 0.0 ELEM 3
The cross-sectional shape of element 3 will look like:
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3.19. DESI
The DESI command enables section information from the structural analysis to be overridden to account
for design requirements. The analyst should note that making large changes to section properties will
cause modifications to the element stiffness which will invalidate the results of the analysis. It is recommended that upon obtaining a satisfactory section, a full re-analysis is performed. Geometric section
properties will be calculated for all section types (except PRI). A section name may be specified instead
of providing explicit section dimensions. The section name may be one already specified in the ASAS
analysis, exist in an external library file, or may be defined using a PROF command.
Parameters
DESI
Keyword
type
Alphanumeric keyword specifying the section type for this list of elements, groups or geometric properties.
Section types currently available are:
TUB
Tube
WF
Doubly symmetric Rolled I-section (e.g. UB, UC, Joist, WFC, WF)
RHS
Rectangular Hollow Section (RHS)
BOX
Fabricated Box Section
PRI
Rectangular Solid Section
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DESI
FBI
Fabricated I-section (NS3472 only)
CHAN
Channel section
ANGL
Angle section
TEE
Tee section
sdims
Section dimensions (Real).
GYRA
Keyword to denote that radii of gyration follow.
gvals
Radii of gyration. Up to two values may be specified for RY and RZ respectively. A third value, RT,
may be given for WF and FBI section types. Values not provided are automatically computed by the
program (Real).
PROF
Keyword to denote that a section name follows.
section
Name of the section (up to 12 alphanumeric characters).
END1
Keyword to denote that the section properties are applied to the first step of the element.
END2
Keyword to denote that the section properties are applied to the last step of the element.
STEP
Keyword to denote that a step number follows:
integer
Step number to which the section properties are referenced (Integer).
ELEM
Keyword to denote selection by element numbers.
GROU
Keyword to denote selection by element group numbers. Only applicable for ANSYS Asas based analyses.
PROP
Keyword to denote selection by geometric property integer.
integer list
List of user element numbers, groups or geometric property numbers. If a step reference is given only
that step for elements specified within the element list, group list or geometric property number list are
assigned the section property values (Integer).
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Usage
Optional for command data selecting TUBE elements or when sections have been specified in the ASAS
analysis, otherwise compulsory for all other available section types.
Notes
1. A detailed description of each section type is given in Appendix D.
2. TUBE elements must not be assigned non-tubular sections.
3. See the introduction to the Command Reference section for details on the priority of assigning data.
4. If sections have been specified in the ASAS analysis any values not defined will default to those available
from the structural database. If sections were not utilized in the ASAS analysis, no defaults exist. (Only
applicable for ANSYS Asas based analyses.)
5. The channel, angle tee and non-symmetric fbi and box sections are only available for stress calculations
using the POST command set. No code checking is currently possible on these section types.
6. If a section is referenced using PROF, the section definition will be searched for in the following order
(options b and c are only applicable for ANSYS Asas based analyses):
a. In a PROF command within the current data file.
b. In the ASAS structural database for this analysis.
c. In a specified external section library.
7. A prismatic section, PRI, must be defined using PROF.
Examples
DESI
DESI
DESI
DESI
DESI
DESI
FBI 1.4 O.9 O.O2 O.O15 PROP 427
BOX 1.2 0.8 0.02 0.02 ELEM 20 TO 26
PROF W12x8 STEP 2 ELEM 147262
RHS 1.2 0.8 0.025 END1 ELEM 100 101 104
WF 1.3 0.8 0.015 0.012 GYRA 0.18 0.55 0.21 GROU 20
TUB 1.0 0.1 ELEM 500
3.20. DS449
The DS449 (or DS44) command requests ultimate limit state strength checks to the Danish Standards
DS449 (Ref. 9) and DS412 (Ref. 10) for tubular members.
When BEAMST is run in stand-alone mode, the program can be used for member checks only and
so command JOIN is not allowed.
Parameters
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EFFE
DS449
Keyword
MEMB
Keyword to select member ultimate limit state checks.
JOIN
Keyword to select joint ultimate limit state checks.
HIGH
Keyword to specify the high safety class.
NORM
Keyword to specify the normal safety class.
A0, A, B, C, D
Keywords to select the curve type from the DS412 column buckling curves.
Usage
Compulsory for DS449 stress checks. Must be first command within the DS449 Command data block.
Notes
1. When BEAMST is run in stand-alone mode, the program can be used for member checks only and so
command JOIN is not allowed.
2. A list of all commands applicable to the DS449 Command data block is given in the DS449 Theory section.
3. If none of the parameters are specified the defaults are: DS449 MEMB HIGH A
Examples
DS449 MEMB NORM
DS449 JOIN
3.21. EFFE
The EFFE command is used to specify the effective length factors Ky and Kz used in calculating slenderness ratios K /r for column buckling calculations about each axis.
Parameters
EFFE
Keyword
value1, value2
Ky and Kz respectively (Real).
ELEM
Keyword to denote element list follows.
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GROU
Keyword to denote selection by element group number. Only applicable for ANSYS Asas based analyses.
integer list
List of user element numbers. (Integer).
Usage
Optional for all member checking command data blocks.
Notes
1. If only value1 is specified, Ky and Kz are both set to it; otherwise Ky is set to value1 and Kz to value2.
2. Elements for which the effective length factors are not specified have default value of 1.0.
3. If Ky or Kz exceeds 1.0 then the member is deemed free to sway in the relevant plane.
Examples
EFFE O.8 ELEM 21 TO 35
EFFE O.8 1.O ELEM 1O8 1O9 112
3.22. ELEM
The ELEM command specifies the elements to be reported. This command can be repeated as many
times as required. It is sometimes convenient to be able to specify a range of elements and subsequently
exclude some of that range - the NOT command word is provided for this purpose. When used in this
way, the order of the ELEM commands is important. The final setting for each element is the one used
to produce the report. In an ANSYS Asas based analysis, the ELEM command may also be used in conjunction with the GROU command to select elements for reporting not referenced by the GROU command.
Parameters
NOT
Keyword to denote that the specified elements are not to be processed.
ELEM
Keyword
integer list
List of user element numbers (Integer).
Usage
Optional for POST Command data block and all member checking command data blocks. At least one
ELEM (or GROU) command must be present in such command data.
Notes
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ELEV
1. The NOT command word has a special effect if it is used on the first ELEM command: all the elements
are selected except for those specified in this command. On all subsequent ELEM commands it merely
has the effect of rejecting the specified elements.
Examples
ELEM ALL
ELEM 6 to 1O
ELEM 12 14 16 TO 2O
ELEM 1 to 1O
NOT ELEM 4 6
3.23. ELEV
The ELEV command is used to specify mean water and seabed levels, tide and surge heights and sea
water density for calculation of hydrostatic pressure.
Parameters
ELEV
Keyword
value1
Mean Water Level relative to the water axes (Real).
value2
Sea Bed Level relative to the water axes (Real).
value3
Density of Sea Water (Real).
value4
Tide Height (Real).
value5
Surge Height (Real).
Usage
Compulsory for all command data blocks examining hydrostatic pressure effects.
Notes
1. The static water depth is taken to be the sum of Mean Water Depth, Tide, and Surge Heights.
Examples
ELEV 150.0 -5.0 1.025
ELEV 450.0 10.0 63.0 9.0 4.0
ELEV 454.0 10.0 63.0 9.0
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3.24. END
The END command is used to terminate a command data block.
Parameters
END
Keyword
Usage
Compulsory to terminate all command data blocks.
Notes
1. The END command must be followed by the next command data block header or a STOP command to
terminate the BEAMST data.
3.25. EXTR
The EXTR command is used to specify which basic and/or combined loadcases are allowed overstress
for extreme/storm conditions.
Parameters
EXTR
Keyword
integer list
List of basic and/or combined user loadcase numbers (Integer).
Usage
Optional for all stress checking command data blocks.
Notes
1. All user loadcase numbers must be explicitly defined, no shorthand syntax is permissible.
Examples
EXTR 2 4
EXTREME 1 5 7 10
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FORC
3.26. FILES
The FILES command is used to define the prefix name for the backing files created in this run. Only
applicable to an ANSYS Asas based analysis.
The FILES command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
FILES
Keyword
fname
Prefix name for any backing files created by this run. (Alphanumeric, 4 characters, first character must
be alphabetic).
Usage
Optional, if omitted file name defaults to project name.
Notes
1. fname is used as a prefix for all files created during the current run. The four characters are appended
with two digits in the range 12 to 35 to create each individual file. This name will also be used by default
for the plotfile name, see the SAVE command.
Examples
FILES BILL
3.27. FORC
The FORC command is used to specify the six beam force components at a specified section on a beam.
Important
The FORC command should be used only when running BEAMST in stand-alone mode.
Parameters
FORC
Keyword
forces
Six components of load at the section (Fx, Fy, Fz, Mx, My, Mz) (Real).
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FACT
Keyword to denote that the force position is defined as a ratio of the element length.
factor
Position along the beam from node 1 to the point at which the forces act (Real).
LENG
Keyword to denote that the force position is defined as a length along the beam.
length
Length along the beam from node 1 to the point at which the forces act (Real).
LOAD
Keyword to denote loadcase number follows:
case
Loadcase number (Integer).
ELEM
Keyword to denote element number follows:
elno
User element number to which these forces apply (Integer).
Usage
Applicable to all command data blocks in stand-alone mode only.
Notes
1. All forces are applied at the section defined in the element’s local axis.
2. Any combination of position and loadcase number for which no FORC data is specified will be assumed
to have zero forces.
3. If any combination of position and loadcase number has more than one FORC command specified then
the forces will be summed.
4. It is the user’s responsibility to ensure that the specified force data is correct.
Examples
FORC 1.23 2.34 3.45 4.56 5.67 6.78 FACT 0.3 LOAD 3 ELEM 10
FORC 3.1 4.1 5.1 6.1 7.1 8.1 LENG 10. LOAD 6 ELEM 7
3.28. GAPD
The GAPD command is used to specify a default gap or eccentricity dimension. This value is used if
none is specified in the TYPE command. A negative value is not allowed.
Parameters
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GRAV
GAPD
Keyword
value
Gap dimension (Real).
Usage
Optional, for X or K joint punching shear and nominal load command data blocks only. The command
is not used for Y joints.
Notes
1. If an entered value is less than the default of 50.8mm/2 inches a warning message is printed.
2. If the GAPD command is omitted then:
• For API 21st Edition: the geometry is used to calculate the gap; unless specified in the TYPE command
.
• For Pre-API 21st Edition: a default value of 50.8mm or 2 inches is used and this is only applied to K
joints.
3.29. GRAV
The GRAV command is used to define the relationship of structure to water surface axes by specifying
the value and direction of the gravitational acceleration relative to the structure axis system.
Parameters
GRAV
Keyword
value1
Gravitational acceleration component in the global X axis of the structure (Real).
value2
Component in the global Y axis (Real).
value3
Component in the global Y axis (Real).
Usage
Compulsory for all command data blocks examining hydrostatic pressure effects.
Notes
1. The GRAV command defines the direction of the gravitational vector (-Zwater) with respect to the
structure (global) axis system.
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2. If the components of gravitational acceleration are given as (0,0,-g) the structure and water axes are coincident with the Z-axis directed vertically upwards. This is always the case in a Mechanical APDL analysis.
Examples
GRAV 0.0 0.0 -9.81
GRAVITY 7.246 -2.473 6.133
3.30. GROU
The GROU command is used to select which ASAS groups are to be reported. This command is only
applicable to an ANSYS Asas based analysis. This command can be repeated as many times as required.
It is sometimes convenient to be able to select elements by their group numbers and to be able to
extend or exclude discrete elements or ranges of elements from the report. The ELEM and NOT ELEM
commands may be used in conjunction with the GROU command for this purpose. For extension and
exclusion purposes, the order of the ELEM commands can be important (see ELEM command).
Parameters
GROU
Keyword
integer list
List of ASAS group numbers (Integer).
Usage
Optional for POST command data block and all member checking command data blocks. At least one
ELEM or GROU command must be present in member command data blocks.
Examples
GROU 1 3 6 10 TO 15
NOT ELEM 8 10 16
GROU ALL
NOT ELEM 8 10 16
GROU 1 3 6 10 TO 15
ELEM 96 105 TO 123
3.31. HYDR
The HYDR command is used to specify loadcase dependent hydrostatic pressure load factors used in
the computation of the design hydrostatic head in API LRFD or ISO hydrostatic checks.
Parameters
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ISO
HYDR
Keyword
gammad
Hydrostatic pressure load factor (Real).
CASE
Keyword denoting loadcase numbers follow.
integer list
List of user selected basic and/or combined loadcases (Integer).
Usage
Only used for API LRFD HYDR or ISO HYDR checks. Optional (see Note 1 below).
Notes
1. For loadcases not specified using this command a value of 1.3 will be assumed. This corresponds to the
operating conditions.
2. All user loadcase numbers must be explicitly defined, no shorthand syntax is permissible.
Examples
HYDR 1.1 CASE 5 6
3.32. ISO
The ISO command selects the International Standard ISO 19902 check (Ref. 27).
Parameters
ISO
Keyword
edition
Selects the edition of the ISO code to be used in the checks. Valid keyword is ED1 (Edition 1).
MEMB
Keyword to select member capacity checks.
HYDR
Keyword to select hydro-static collapse checks for tubulars.
JOIN
Keyword to select joint checks for tubulars.
Usage
Compulsory for all ISO code checks. Must be the first command within the ISO Command data block.
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Notes
1. A list of all commands applicable to the ISO command data block appears in the ISO Theory section.
3.33. JOB
The JOB command is used to define the type of analysis being performed.
The JOB command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
JOB
Keyword
POST
Keyword indicating post-processing of an analysis.
NEW
Keyword
CHEC
Keyword indicating BEAMST is being used in stand-alone mode. See Appendix F.
Usage
Compulsory.
Examples
JOB POST
JOB NEW CHEC
3.34. JOIN
The JOIN command is used to select the nodes to be included in joint checks. This command can be
repeated as many times as required. It is sometimes convenient to be able to specify a range of node
numbers and subsequently exclude some of that range; the NOT command word is provided for this
purpose. In this way the order of the JOIN commands can be important. The final setting for each node
is the one used.
Parameters
NOT
Keyword to denote that the specified joints are not to be processed.
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LIBR
JOIN
Keyword
nodes
List of nodes (Integer).
Usage
Compulsory for all joint command data blocks.
Notes
1. The NOT command parameter has a special effect if it is used on the first JOIN command: all the joints
are selected except for those specified in this command. On all subsequent JOIN commands it merely
has the effect of rejecting the specified joints.
2. For a joint to be identified as multi-noded all nodes must be included in the joint check.
Examples
JOIN ALL
JOIN 6 to 1O
JOIN 12 14 16 TO 2O
JOIN 1 to 1O
NOT JOIN 4 6
3.35. LIBR
The LIBR command is only required if section libraries were used in the ASAS analysis. The command
provides the name of an external file which contains beam section information for use in the stress
calculations. Only applicable to an ANSYS Asas based analysis.
The LIBR command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
LIBR
Keyword
filenm
Up to 6 character name of an external (physical) file that contains section library information for beam
type elements.
Usage
Optional.
Notes
1. If a section library was utilized in ASAS and the LIBR command line is omitted, the library file from the
analysis will be automatically adopted.
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2. The library file selected, either using the LIBR command or defaulting to the analysis file, must be present
in the user’s work area.
3. If the library file specified is different to that used in the original analysis it is important that all section
identifiers which are to be referenced are present in the new library.
3.36. LIMIT
The limiting values defined below are built into BEAMST, but for API WSD JOIN these may be overwritten
at the user’s discretion, using one or more LIMIT commands.
Parameters
LIMIT
Keyword
limval
Keyword indicating parameter for which default applicability limit is to be overwritten. (Alphanumeric)
Permitted values are:
• BETA
• GAMMA
• TAU
• THETA
minval
Lower applicability limit for parameter limval (Real).
maxval
Upper applicability limit for parameter limval (Real).
Usage
Only used for API WSD JOIN and ISO JOIN checks. Optional (see Note 1 below).
Notes
1. Default applicability limits are as follows (using the standard parameter definitions):
0.2 ≤ BETA ≤ 1.0
10 ≤ GAMMA ≤ 50
0 ≤ TAU ≤ 1.0
300 ≤ THETA ≤ 900
3.37. MATE
The MATE command is used to define the material properties.
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MCOF
Important
The MATE command should only be used when running BEAMST in stand-alone mode.
Parameters
MATE
Keyword
youngs
Young’s modulus (Real).
poisson
Poisson’s ratio (Real).
ELEM
Keyword to denote that element list follows.
GROU
Keyword to denote that group list follows. Only applicable to an ANSYS Asas based analysis.
integer list
List of user element or group numbers (Integer).
Usage
Applicable to all command data blocks in stand-alone mode only.
Notes
1. See the introduction to the Command Reference section for details on the priority of assigning data.
Examples
MATE 207000. 0.3 ELEM 1 2 3 4
3.38. MCOF
The MCOF command is used to specify the global partial material coefficient utilized in the DS449,
NORSOK and NPD code checks. The coefficient(s) may be loadcase dependent.
Parameters
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MCOF
Keyword
value
Partial material coefficient (Real).
PARA
Optional keyword to denote that the value defined is to be assigned to a particular material parameter
given by the following keyword.
YIEL
Keyword to denote yield stress parameter.
PUNC
Keyword to denote punching strength parameter. Applicable only to DS449.
ELAS
Keyword to denote modulus of elasticity parameter. Applicable only to DS449.
LOAD
Keyword to denote that loadcase numbers follow:
case
List of loadcase numbers to which the value of the material coefficient is to be assigned. ALL is not
permitted (Integer).
Usage
Optional - applicable to DS449, NORSOK and NPD command data blocks only
Notes
1. If PARA and its associated keywords are omitted, then PARA YIEL is assumed.
2. Explicit definition of a parameter coefficient (using the PARA keyword) will override any definition without
a parametric statement.
3. For loadcases not defined using a MCOF command the following defaults will be utilized. The DS449
values reflect the strict material control definition in that code.
4. For NORSOK the default material partial safety factor is 1.15 for tension and joint strength. It varies for
compression (including hydro-static checks). If a value of 1.15 is input here the default calculations will
be assumed for hydrostatic and compression cases. Values other than 1.15 + 0.001 will use the input
value for all checks
Table 3.1: Default values of resistance factorsa
Parameter
Keyword
NPD
NORSOK
DS449 Normal
DS449 High
Material Coefficient γm
YIEL
1.15
1.15
-
-
Yield Stress γy
YIEL
-
-
1.09
1.21
Punching Strength γp
PUNC
-
-
1.21
1.34
Modulus of Elasticity γE
ELAS
-
-
1.34
1.48
a
The connection resistance factor depends upon the joint type and load component being considered. The value of 0.95 is used for
all variants except axial tension for T, Y, and X joints, where a value of 0.90 is utilized.
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MFAC
Examples
MCOF 1.5 PARA PUNC LOAD 2
MCOF 1.38 LOAD 1 8 9
3.39. MFAC
The MFAC command is used to define the moment reduction factors to be used in the BS5950 overall
buckling check.
Parameters
MFAC
Keyword
facy
Moment reduction factor for My (Real).
facz
Moment reduction factor for Mz (Real).
LOAD
Keyword to denote that loadcase number follows:
lcn
Loadcase number (Integer).
ELEM
Keyword to denote that element list follows:
integer list
List of user element numbers (Integer).
Usage
Optional for BS59 Command data block only.
Notes
1. For elements with no MFAC data line facy and facz will be taken as 1.0.
2. If facz is omitted from the MFAC data line facz will be taken as equal to facy.
3. If LOAD and lcn are omitted from the MFAC data line then the specified facy and facz values will be
assumed to apply to all loadcases.
Examples
MFAC 0.7 0.5 LOAD 1 ELEM 6 8
MFAC 0.6 ELEM 1 2
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3.40. MLTF
The MLTF command is used to define the moment reduction factor to be applied to the lateral torsional
buckling component in the BS5950 overall buckling check.
Parameters
MLTF
Keyword
value
Lateral torsional buckling moment reduction factor (Real).
LOAD
Keyword to denote that loadcase number follows:
lcn
Loadcase number (Integer).
ELEM
Keyword to denote that element list follows:
integer list
List of user element numbers (Integer).
Usage
Optional for BS59 Command data block only.
Notes
1. For elements with no MLTF data lines, value will be taken as 1.0
2. If LOAD and lcn are omitted from the MLTF data line then the specified value of value will be assumed
to apply to all loadcases.
Examples
MLTF 0.6 ELEM ALL
MLTF 0.6 ELEM ALL
MLTF 0.8 LOAD 1 ELEM 10
3.41. MOVE
The MOVE command is used to specify the origin of the Water Axes relative to the structure Global
Axes origin.
Parameters
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NORS
MOVE
Keyword
value1
X-coordinate of the Water Axes origin in the Global Axes (Real).
value2
Y-coordinate of the Water Axes origin in the Global Axes (Real).
value3
Z-coordinate of the Water Axes origin in the Global Axes (Real).
Usage
Optional for all command data blocks examining hydrostatic pressure effects.
Notes
1. If omitted the origins of the Water and the Global Axes origin are assumed coincident. This is always the
case for a Mechanical APDL analysis.
Examples
MOVE 5.0 20.0 15.0
MOVE -24.0 -10.0 14.6
3.42. NORS
The NORS command selects the NORSOK check (Ref. 24).
Parameters
NORS
Keyword
editcm
Selects the edition of the NORSOK code to be used in the checks. Valid keyword is ED98 (1998 Edition).
MEMB
Keyword to select member capacity checks.
HYDR
Keyword to select hydro-static collapse checks for tubulars.
JOIN
Keyword to select joint checks for tubulars.
Usage
Compulsory for all NORSOK code checks. Must be the first command within the NORSOK Command
data block.
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Notes
1. A list of all commands applicable to the NORS command data block appears in the NORSOK Theory
section.
3.43. NPD
The NPD command selects ultimate limit state compliance checks to NPD/NS3472 regulations (Ref. 5,
Ref. 6 and Ref. 7).
When BEAMST is run in stand-alone mode, the program can be used for member checks only and
so command JOIN is not allowed.
Parameters
NPD
Keyword
ED92
Keyword to select NPD code Edition 1992.
MEMB
Keyword to select member yield and buckling checks.
JOIN
Keyword to select joint punching shear checks.
Usage
Compulsory for all NPD limit state checks. This must be the first command within the NPD Command
data block
Notes
1. When BEAMST is run in stand-alone mode, the program can be used for member checks only and so
command JOIN is not allowed.
2. A list of all commands applicable to the NPD Command data block is given in the NPD/NS3472 Theory
section.
3. If no sub-command is present, MEMB is assumed.
4. If ED92 not selected then Edition 1985 is assumed.
Examples
NPD MEMB ED92
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OPTI
3.44. OPTI
The OPTIons command is used to define the control options for this run.
The OPTI command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
OPTI
Keyword
option
Four character option name, or list of option names. Allowable Options for BEAMST are:
BRIG
Selects Rigorous buoyancy for hydrostatic collapse check. Same as the BRIG command.
DATA
Stop after checking the data. This is useful whenever careful checking is required. This option overrides
all reports selected locally within command data blocks on the PRIN command(s) except the XCHK
Report.
GOON
Proceed even after printed WARNINGS. This option allows the run to continue despite doubtful data.
JRNG
Perform joint checks based on the lesser strength, from strengths based on actual geometric values,
with strengths evaluated by imposing the geometric limits where validity ranges are exceeded. Valid
for API WSD JOIN and ISO JOIN checks only.
NOBL
Do not print the BEAMST run title pages.
NOTR
Do not write the results to the User Results Storage Database.
PRNO
This option allows the first 20 lines of BEAMST data to be echoed to the print file. All remaining data
is suppressed.
Usage
Optional.
Notes
1. BEAMST will not print any results unless requested. No options exist to request such printing, all results
reports are requested through the PRIN command. This allows users to vary the quantity and type of
results printed to their requirements.
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BEAMST Command Reference
2. BEAMST will print forces and stresses in the reports selected as normal numbers without scientific notation
(i.e. the FORF option which exists in other programs within the ASAS suite is automatically invoked
within BEAMST). The output defaults to scientific notation if a line of forces or stresses has very large or
very small values.
Examples
OPTIONS DATA NOBL
3.45. PHI
The PHI command is used to specify the load dependent parameter, φ, used in the determination of
the lateral buckling strength of beams for NS3472E.
Parameters
PHI
Keyword
value
Is the explicitly defined parameter (Real).
AUTO
Requests that automatic calculation of PHI is carried out using the formula:
where M1 and M2 are the moments at the ends of the beam about the strong axis and M1 ≥ M2
LOAD
Keyword to denote that loadcase number follows:
case
Loadcase number to which the value of φ is to be assigned (Integer).
ELEM
Keyword to denote that element list follows:
integer list
List of user element numbers (Integer).
Usage
Optional - applicable to NPD command data blocks only
Notes
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PRIN
1. If the loadcase number is not defined all loadcases will be assigned the value of φ for the elements
specified.
2. Explicit definition of φ on a loadcase basis will override any definition without a loadcase number for a
given element. Automatic calculation of φ will be overridden by an explicit definition for a given element.
3. If AUTO is chosen for loadcase specific data, this will override any specific value of φ defined for an element
without the loadcase provided.
4. In the absence of a PHI definition for an element a default value of 1.0 will be utilized.
Examples
PHI 2.0 LOAD 2 ELEM 1 5 6
PHI AUTO ELEM ALL
PHI 1.5 ELEM 5 TO 10
3.46. POST
The POST header command is used to request property, force and stress reports but without checks
to a specific design code of practice.
Parameters
POST
Keyword
Usage
Compulsory for all general post-processing. Must be the first command within the POST Command
data block.
Notes
1. A list of all commands applicable to the POST Command data block is given in the POST Theory section.
2. There are no sub-commands.
3.47. PRIN
The PRIN command specifies the reports to be printed.
Parameters
PRIN : Keyword.
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type : Keyword indicating type of report required or units to be used. See table below for available
keywords.
params : Additional parameters applicable to each type:
Table 3.2: PRINT Command Parameters
Type
Meaning
Additional Parameters
XCHK
Input Data Cross Check Report
None
PROP
Member Geometry and Material
Property Report
None
FORC
Member Force Report
None
STRE
Member Stress Report
None
UNCK
Unity Check Report
None
SUM1
Highest yield and buckle combined stress unity checks
ex1, ex2 specify exceedence values (report SUM4 only)
FAIL report failed members only BOTH print both full
summary and failed member reports uclim utilization
limit for failure reports
SUM2
Highest buckle check plus all
unity checks at section with
highest yield combined stress
unity check
See SUM1 above
SUM3
Highest unity check
See SUM1 above
SUM4
3 worst unity checks plus distribution of unity check values
See SUM1 above
SUM5
Highest member forces and moments
See SUM1 above
FUNI
Change force units in reports
name1 length unit name2 force unit
SUNI
Change stress units in reports
name1 length unit name2 force unit
All
Print all appropriate reports
None
Usage
Optional - for defaults see Note 8 below.
Notes
1. The reports applicable to each type of Code Check are given in each of the tables: Table 3.3: Output Reports
Available for API/AISC Code Checks (p. 97), Table 3.4: Output Reports Available for European Code
Checks (p. 98), Table 3.5: Output Reports Available for International Standards Code Checks (p. 99).
2. BEAMST automatically filters out requested reports which are not available for the type of check/postprocessing selected. Such redundant requests do not induce data or execution errors.
3. Exceedence values are only appropriate for summary report number 4 (SUM4) and if omitted default to
1.0 and 0.5.
4. Utilization limits are available for summary reports 1-4. For summary report number 4 (SUM4), the exceedence values MUST precede BOTH/FAIL.
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PRIN
5. If units are specified both length and force units must be supplied. The valid unit names are listed under
the UNIT command. These units override any results units defined in the Preliminary data (see UNIT).
6. FUNI is only valid for NPD Unity Check Reports.
7. If this command is omitted, the following defaults apply:
Command
Default
AISC WSD ALLO
AISC LRFD MEMB
API WSD ALLO
API LRFD MEMB
PRIN SUM1
API WSD HYDR
API LRFD HYDR
NORS MEMB
NORS HYDR
API WSD PUNC
API WSD NOMI
API LRFD JOIN
PRIN SUM3
NPD JOIN
NORS JOIN
DS449
POST
No Default
ANPD MEMB
BS59
Output Reports
BEAMST has a number of different types of output reports that may be printed selectively using the
PRIN command. The reports available are described in the following sections and are summarized in
the following tables.
Note, if the command PRIN ALL is used then all available reports for the given Code Check will be output.
Table 3.3: Output Reports Available for API/AISC Code Checks
Report
AISC/API AISC
WSD
LRFD
ALLO
MEMB
API
WSD
HYDR
API
WSD
NOMI
(<
ED21)
API
WSD
PUNC
(<
ED21)
API
WSD
JOIN
(>
ED21)
API
LRFD
MEMB
API
LRFD
HYDR
API
LRFD
JOIN
Data Echo
Y
Y
Y
Y
Y
Y
Y
Y
Y
Command
Summary
Y
Y
Y
Y
Y
Y
Y
Y
Y
Cross Check
Y
Y
Y
Y
Y
Y
Y
Y
Y
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Report
AISC/API AISC
WSD
LRFD
ALLO
MEMB
API
WSD
HYDR
API
WSD
NOMI
(<
ED21)
API
WSD
PUNC
(<
ED21)
API
WSD
JOIN
(>
ED21)
API
LRFD
MEMB
API
LRFD
HYDR
API
LRFD
JOIN
Member
Properties
Y
Y
Y
-
-
-
Y
Y
-
Member
Force
Y
Y
Y
-
-
-
Y
Y
-
Member
Stress
Y
Y
Y
-
-
-
Y
Y
-
Unity Check
Y
Y
Y
Y
Y
Y
Y
Y
Y
No. 1
Y
Y
Y
-
-
-
Y
Y
Y
No. 1 (FAIL)
Y
Y
Y
-
-
-
Y
Y
Y
No. 2
Y
-
-
-
-
-
-
-
-
No. 2 (FAIL)
Y
-
-
-
-
-
-
-
-
No. 3
Y
Y
-
Y
Y
Y
Y
-
Y
No. 3 (FAIL)
Y
Y
-
Y
Y
Y
Y
-
Y
No. 4
Y
-
-
Y
Y
Y
-
-
-
No. 4 (FAIL)
Y
-
-
Y
Y
Y
-
-
-
No. 5
-
-
-
-
-
-
-
-
-
Summary Reports
Table 3.4: Output Reports Available for European Code Checks
Report
BS59MEMB
DS449MEMB
DS449JOINNPDMEMB
NPD
JOIN
NORSOKMEMB
NORNORSOKHY- SOKDR
JOIN
POST
Data
Echo
Y
Y
Y
Y
Y
Y
Y
Y
Y
Command
Summary
Y
Y
Y
Y
Y
Y
Y
Y
Y
Cross
Check
Y
Y
Y
Y
Y
Y
Y
Y
Y
Member
Properties
Y
Y
-
Y
-
Y
Y
-
Y
Member
Force
Y
Y
-
Y
-
Y
Y
-
Y
Member
Stress
Y
Y
-
Y
-
Y
Y
-
Y
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PRIN
Report
BS59MEMB
DS449MEMB
DS449JOINNPDMEMB
NPD
JOIN
NORSOKMEMB
NORNORSOKHY- SOKDR
JOIN
POST
Unity
Check
Y
Y
Y
Y
Y
Y
Y
Y
-
Y
Y
-
Y
-
Y
Y
Y
-
Summary
Reports
No.
1
Y
Y
-
Y
-
Y
Y
Y
-
No.
1
(FAIL)
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
-
No.
2
Y
Y
Y
Y
Y
Y
-
Y
-
Y
Y
Y
Y
Y
Y
-
Y
-
Y
Y
Y
Y
Y
-
-
-
-
Y
Y
Y
Y
Y
-
-
-
-
-
-
-
-
-
-
-
-
Y
No.
2
(FAIL)
No.
3
No.
3
(FAIL)
No.
4
No.
4
(FAIL)
No.
5
Table 3.5: Output Reports Available for International Standards Code Checks
Report
ISO MEMB
ISO HYDR
ISO JOIN
Data Echo
Y
Y
Y
Command Summar
Y
Y
Y
Cross Check
Y
Y
Y
Member Properties
Y
Y
-
Member Force
Y
Y
-
Member Stress
Y
Y
-
Unity Check
Y
Y
Y
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Report
ISO MEMB
ISO HYDR
ISO JOIN
No. 1
Y
Y
Y
No. 1 (FAIL)
Y
Y
Y
No. 2
-
-
-
No. 2 (FAIL)
-
-
-
No. 3
Y
-
Y
No. 3 (FAIL)
Y
-
Y
No. 4
-
-
-
No. 4 (FAIL)
-
-
-
No. 5
-
-
-
Summary Reports
Data Echo Report
The Data Echo Report echoes the input data for BEAMST together with any input error or warning
messages that may result.
Command Summary Report
The Command Summary Report contains details of the type and extent of the post-processing selected.
For code checking runs of BEAMST, this report begins with an expanded form of the header and subheader commands detailing the code checks being performed. For all BEAMST runs the details of the
input and output dimensional units, selected loadcases and selected reports are summarized next. Finally
any member (‘or joint’) or joint invariant data that is pertinent to the type of post-processing selected
is specified. The Command Summary Report contains details of the input and output dimensional units,
selected loadcases and selected reports.
Input Data Cross Check Report
The Input Data Cross Check Report presents the input data in an expanded tabular format. This enables
the user to quickly validate the data and also enables BEAMST to highlight exactly where any conflicts
or data errors occur in the data.
For member calculations a list of sections to be reported is included for all elements selected. By default
only the end points and any step positions are reported. Other sections may be requested using the
SECT command.
Member Reports
Three member reports are available: Member Properties, Member Forces and Member Stresses. These
reports are printed for each selected element in sequential order:
Property - Force - Stress
These reports are not available for joint checks and are optional for all other types.
Member Property Report
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PRIN
The Member Property Report gives all the relevant geometric and material data for each selected
member (element). The element number and element group is given at the top of the report along
with the units in use. The element’s nodes and coordinates are printed next along with the element’s
length and associated effective and unbraced lengths. The slenderness ratio, k /r is also printed.
The cross-section properties are then printed for each step of the element in turn. These consist of the
flexural properties (from ASAS or those associated with DESI commands), the material properties (from
ASAS and YIEL command) and the section dimensions (from ASAS or DESI command).
Member Force Report
The Member Force Report gives the six components of force at each section for each selected member
(element). The element number, its node numbers and group number are given at the top of the report
along with the units in use. The forces are then printed for each of the element’s sections for each
loadcase in turn. The section positions are identified by number and ratio of position to element length.
The first and last sections will be at position 0.00 and 1.00 and relate to the ends of the element. Any
intermediate sections are either those specified by a SECT command or at the position of a step change
in cross-section properties. The section values are followed by the maximum value found at any section
within the element and also the position at which the maximum occurs.
When the SEAR command is in use the maximum may occur at a section position not reported in the
section data above. This is because the SEAR command causes additional sections on the element to
be searched without reporting.
The final two columns of the Member Force Report give the free moments in the local Y and Z directions.
Member Stress Report
The Member Stress Report gives the member stresses at each section for each selected member (element).
The element number, its node numbers and group number are given at the top of the report along
with the units in use. The stresses are then printed for each of the element’s sections for each loadcase
in turn. The section positions are identified by number and ratio of position to element length. The first
and last sections will be at position 0.00 and 1.00 and relate to the ends of the element. Any intermediate
sections are either those specified by a SECT command or at the position of a step change in crosssection properties. The section stresses are followed by the maximum stress found at any section
within the element and also the position at which the maximum occurs.
When the SEAR command is in use the maximum may occur at a section position not reported in the
section data above. This is because the SEAR command causes additional sections on the element to
be searched without reporting.
The final four columns of the Member Stress Report give the combined axial stress at four locations on
the section denoted A, B, C and D. These locations and the methods of combining the stress are given
individually for each section type in Appendix D.
Unity Check Report
A single Unity Check Report is available in BEAMST for each type of Command data block which performs
a stress check to a design code and the PRIN parameter UNCK will select it. The report comprises
member acting stresses where such stresses differ or are not available from the Member Stress Report,
allowable stresses and unity checks appropriate to the design code check selected. Messages appropriate
to the allowable stresses and unity check(s) which result appear on the right-hand side of the report
as a four letter code and are expanded in a Glossary printed at the end of the report. Members ‘(or
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BEAMST Command Reference
joints’) or joints which ‘FAIL’ the unity check(s) or violate any design code clause are indicated so in
this messages column. All unity check values printed are limited to a maximum of 99.99.
The Unity Check Report for member checks is printed as a separate report for each element selected
and if selected together with Member Reports will be printed in the sequential order:
Properties - Force - Stress - Unity Check.
For joint checks, the Unity Check Reports for all selected joints are printed together.
The Unity Check Reports are further explained in the appropriate code check detailed description sections.
Summary Reports
Five types of Unity Check Summary Reports are in general available, examples of which are described
in the individual code check sections of this manual. For availability of each type refer to the tables
above.
Summary Report number 1 comprises the highest yield and buckle combined stress unity checks and
their components for each selected element over all loadcases selected.
Summary Report number 2 comprises the highest buckle check and all unity checks at the section with
the highest yield combined stress unity check for each selected element over all loadcases selected.
Summary Report number 3 comprises the highest unity check for each selected loadcase for each element
or joint selected.
Summary Report number 4 comprises the three worst unity checks for each selected group or joint
together with a distribution of unity check values. The distribution is characterized by the number of
unity checks exceeding 1.0, the number less than 0.5 and the number in the mid-range. These default
‘exceedence values’ may be altered by the user by the addition of further parameters to the PRIN SUM4
command.
Summary Report number 5 provides information about the highest member forces and moments for
each selected group. For each force type (axial, shear, torque and bending) the worst four values are
reported together with the element number, loadcase number and position along the element. Separate
tables are printed for maximum positive and maximum negative force values. If spectral loadcases have
been specified then the maximum and minimum values for each of the force types are determined
from the sixteen spectral expansion cases prior to comparing with the forces from other loadcases. A
spectral loadcase, therefore, can appear only once for a given element/force type within a group.
If Summary Reports are selected in any Command data block presented to BEAMST, the program will
automatically open an additional results file and write the Summary Reports selected to it. This additional
output file allows the Summary Reports to be accessed and viewed quicker by the user. The name of
the file written to is xxxxBM where xxxx is the fname parameter from the FILES command
For examples of the Unity Check Reports, see the appropriate code check detailed description sections.
Examples
PRIN XCHK PROP STRE SUNI MILLIMETRE KNEWTON
PRIN SUM3 SUM4 1.33 0.5 FAIL SUNI MM KN
PRIN SUM3 BOTH 0.95 SUM4 1.33 0.5 FAIL 0.85 SUNI MM KN
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PROF
3.48. PROF
The PROF command enables a section profile to be defined in terms of type, dimensions and properties
for use with the DESI command.
Parameters
PROF
Keyword
section
Name of the section (up to 12 alphanumeric characters).
type
Alphanumeric keyword specifying the section type. Section types currently available are:
TUB
Tube
WF
Doubly symmetric Rolled I-section (e.g. UB, UC, Joist, WFC, WF)
RHS
Rectangular Hollow Section (RHS)
BOX
Fabricated Box Section
PRI
Rectangular Solid Section
FBI
Fabricated I-section (NS3472 only)
CHAN
Channel Section
ANGL
Angle Section
TEE
Tee Section
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XSEC
Keyword to denote that section dimensions follow:
dimensions
Section dimensions. See Appendix D for the details of which dimensions are required for each section
type (Real).
FLEX
Keyword to denote that section properties follow:
flexprops
Section geometric properties (Real).
For all section types, this is AX, IZ, IY, J, AY, AZ where:
AX
Cross sectional area
IZ
Principal moment of inertia about element local Z axis
IY
Principal moment of inertia about element local Y axis
J
Torsion constant
AY
Effective shear area for forces in element local Y direction
AZ
Effective shear area for forces in element local Z direction
proptype
Name of the geometric property to be defined. Valid names are AX, IZ, IY, J, AY, AZ with the meaning
as above.
prop
Value to be assigned to the named geometric property.
PROF
Keyword
GYRA
Keyword to denote that radii of gyrations follow.
radg
Radii of gyration. Up to two values may be specified for RY and RZ respectively. A third value, RT,
may be given for WF and FBI section types.
radtype
Name of radius of gyration to be defined.
radius
Value to be assigned to the specified radius of gyration.
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PROJECT
Usage
Optional for all command data blocks.
Notes
1. For a given section identifier the XSEC information must be provided. FLEX and/or GYRA values may
also be supplied with the following interpretations: If only XSEC is defined, the geometric flexural
properties and radii of gyration will be automatically calculated by the program from the section dimensions. If both XSEC and FLEX commands are utilized, any geometric properties explicitly defined will
overwrite those calculated from the section dimensions. This feature should be used with care since
many codes of practice compute effective section properties, which may be incompatible with those
provided explicitly. If both XSEC and GYRA commands are utilized, any radii explicitly defined will
overwrite those calculated from the flexural properties. The FLEX and GYRA commands may not be
defined without an associated XSEC command.
2. If FLEX and/or GYRA data is required, this must be provided on separate PROF command lines.
Examples
PROFILE
PROFILE
PROFILE
PROFILE
RHS22x16
RHS22x16
BOX19x11
RHS22x16
RHS XSEC 22.5 16.8 0.2 0.8
FLEX 15.32 1164.5 749.81 1443.6
BOX XSEC 19.2 11.6 0.4 0.2
GYRA
3.49. PROJECT
The PROJECT command is used to define the project name for the current run.
The PROJECT command is a preliminary command, and should appear only at the head of the
BEAMST data set.
Parameters
PROJECT
Keyword
pname
Project name for current run (Alphanumeric, 4 characters, first character must be alphabetic).
Usage
Optional, if omitted project name defaults to ASAS.
Notes
1. All runs with the same project name access the same database. A project database consists of one project
file (with a file name consisting of the 4 characters of pname with the number 10 appended), which acts
as an index to other files created under this project, together with those other files.
Examples
PROJECT HIJK
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3.50. QUAK
The QUAK command is used to specify which basic and/or combined loadcases are allowed earthquake
permitted overstress for earthquake/seismic conditions.
Parameters
QUAK
Keyword
integer list
List of basic and/or combined user loadcase numbers (Integer).
Usage
Optional for member allowable stress, hydrostatic collapse and tubular joint punching shear command
data blocks.
Notes
1. All user loadcase numbers must be explicitly defined, no shorthand syntax is permissible.
Examples
QUAK 2 4
QUAK l 19 40 67 72
3.51. RENU
The RENU command is used to alter the loadcase numbers of basic loadcases presented to BEAMST on
files saved from a previous ASAS, RESPONSE or LOCO analysis. Only applicable to an ANSYS Asas
based analysis.
Parameters
RENU
Keyword
oldcase
Basic loadcase number existing on the files saved for BEAMST by a previous analysis (Integer).
INTO
Keyword
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SAFE
newcase
New loadcase number to be assigned to the oldcase. (Integer)
Usage
Optional - may be used in any command data block.
Notes
1. The user is strongly advised if using the RENU command to position it within the command data block
immediately following the Header Command. Any command following it which refers to basic loadcases
must refer to newcase(s).
Examples
RENU 17 INTO 77
RENUMBER 84 INTO 23
RENU 72 INTO 1071
3.52. RESU
The RESU command is used to specify saving of results to the results database.
The RESU command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
RESU : Keyword.
Notes
1. For the results database to be used in any post-processing run with the ASAS solvers a RESU command
must be included in the initial ASAS run to initialize the database.
Examples
RESU
3.53. SAFE
The SAFE command is used to specify loadcase dependent safety factors for hydrostatic collapse checks
and their associated basic and/or combined user loadcase numbers.
Parameters
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SAFE
Keyword
value1
Safety factor for axial compressive loading (Real).
value2
Safety factor for axial tensile loading (Real).
value3
Safety factor for hoop compressive loading (Real).
CASE
Keyword denoting loadcase numbers follow:
integer list
List of user selected basic and/or combined loadcases (Integer).
Usage
Optional for hydrostatic collapse data blocks.
Notes
1. All values not defined default according to loadcase type (as defined by EXTR or QUAK commands) as
follows:
Loadcase Type
Value1
Value2
Value3
Not defined
2.00
1.67
2.00
EXTR
1.50
1.25
1.50
QUAK
1.20
1.00
1.20
2. The value for axial compressive loading is checked against the AISC safety factor for column buckling
under axial compression and the greater of the two is taken.
3. All user loadcase numbers must be explicitly defined, no shorthand syntax is permissible.
Examples
SAFE
SAFE
SAFE
SAFE
1.67
1.30
1.30
1.30
CASE
1.25
0.90
0.90
16
CASE 1 6 10
1.430 CASE 99 102
1.30 CASE 99 102
3.54. SAVE
The SAVE command is used to define the plot file which is to be saved for subsequent display by the
relevant plotting program, or to save the intermediate file.
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SAVE
The SAVE command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
SAVE
Keyword
FEMS
Keyword to save the FEMVIEW plot file.
FEMF
Keyword to save only member forces/moments on the FEMVIEW plot file.
FEMU
Keyword to save only unity check values on the FEMVIEW plot file.
FILES
Keyword
CREATE
Keyword to signify model data is to be included (default).
APPEND
Keyword to signify no model data to be included.
model
Model name to be used by FEMVIEW.
FILE
Keyword to indicate filename follows:
filename
Name of FEMVIEW file to be created.
Usage
Optional.
Notes
1. The plot files are mutually exclusive and only one may be specified within any BEAMST analysis.
2. CREATE/APPEND and following data is only valid for FEMS, FEMF, FEMU.
3. FILE may only be omitted if model is specified.
4. The default interface file will be named nnnnFS for FEMVIEW interface files where nnnn is the backing
file name for files created by this run.
Examples
SAVE FEMS FILE
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3.55. SEAR
The SEAR command is used to request a search for the maximum value of force, stress or unity check
at a series of sections along a beam, in addition to those explicitly requested on the SECT command.
Parameters
SEAR
Keyword
values
Beam search section position (Real).
ELEM
Keyword to denote selection by element number.
GROUP
Keyword to denote selection by element group number. Only applicable to an ANSYS Asas based analysis.
integer list
List of user selected basic and/or combined loadcases (Integer).
Usage
Optional - applicable to all member checking and post-processing command data.
Notes
1. Beam section search positions are defined in the range 0.0 to 1.0 where 0.0 and 1.0 refer to beam ends
1 and 2 respectively.
2. Element definition of section information overrides group number definition. See BEAMST Priority of
Data Assignments (p. 56).
3. If no values are supplied, a default set of up to five positions will be used for each beam. For unstepped
beams, search positions of 0.25, 0.5 and 0.75 will be used. For stepped beams, search positions of 0.1667,
0.3333, 0.5, 0.6667 and 0.8333 will be used.
4. The forces and stresses used in the calculation of the coefficients Cb, Cmy and Cmz and the combined
buckle unity check are obtained by taking the maximum values from all of the sections checked i.e. the
beam ends, step positions for stepped beams and any sections defined by way of SEAR and/or SECT
commands.
5. Results are only reported for sections defined by the SEAR command if they give maximum forces, moments, stresses or unity check values.
Examples
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SECT
SEAR 0.25 0.50 0.75 ELEM 17 84 TO 214
SEARCH 0.50 ELEM ALL
SEAR 0.1 0.9 GROU 0 2 6
SEARCH ELEM 1 TO 55
SEARCH
3.56. SECO
The SECO command is used to specify that certain elements defined by their element, group or geometric property numbers are to be classed as secondary members for checking against allowable stresses
or to be excluded from joint punching shear checks.
Parameters
SECO
Keyword
ELEM
Keyword to denote selection by element number.
GROUP
Keyword to denote selection by element group number. Only applicable to an ANSYS Asas based analysis.
PROP
Keyword to denote selection by geometric property number.
integer list
List of user element numbers, groups or geometric property numbers (Integer).
Usage
Optional for member allowable stress check and joint punching shear checking command data blocks.
Notes
Examples
SECONDARY ELEMENTS 10 15 21
SECO GROUPS 16 TO 24
SECO PROPERTIES 14 17 19 TO 2
SECO ELEM 20 TO 44
SECO GROUP 19 26
SECO PROP 16 14 TO 19
3.57. SECT
The SECT command is used to specify the intermediate beam section positions which are to be reported
for the selected elements or groups.
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BEAMST Command Reference
Parameters
SECT
Keyword
value
Beam section position (Real).
ELEM
Keyword to denote selection by element number.
GROUP
Keyword to denote selection by element group number. Only applicable to an ANSYS Asas based analysis.
integer list
List of user element numbers or group numbers (Integer).
Usage
Optional - applicable to all member checking and post-processing command data.
Notes
1. Beam section search positions are defined in the range 0.0 to 1.0 where 0.0 and 1.0 refer to beam ends
1 and 2 respectively.
2. See the introduction to the Command Reference section for details on the priority of assigning data.
3. Beam end positions (plus step positions for stepped beams) by default are reported in addition to any
beam section positions specified on SECT commands.
4. For a stand-alone BEAMST run, all sections defined by the FORC command together with any sections
defined on the SECT commands are reported. However, those sections which are not given force/moment
values on a FORC command will report zero values, except for the Free Moments.
Examples
SECT 0.25 0.50 0.75 ELEM 17 84 TO 214
SECTION 0.50 ELEM ALL
SECT 0.1 0.9 GROU 0 2 6
3.58. SELE
The SELE command is used to define a combined loadcase title. It may also be used to redefine basic
loadcase titles presented to BEAMST on files saved from a previous ASAS, RESPONSE or LOCO analysis.
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SIMP
Parameters
SELE
Keyword
case
Combined or basic loadcase number (Integer).
title
New loadcase title, up to 40 characters.
Usage
Optional and may be used in any command data block.
Notes
1. A blank space must exist between case and title.
2. Continuation lines are not permitted.
3. If omitted, the basic loadcase titles remain as from the previous analysis and the combined loadcase
titles are blank.
Examples
SELE 17 COMBINED LOADCASE TITLE EXAMPLE
SELECT 82 REDEFINED BASIC LOADCASE TITLE
3.59. SIMP
The SIMP command is used to select elements for which the simplified code check methods described
in BS5950 are to be used. These simplified methods are applicable to plastic and compact members for
the axial plus moment and the overall buckling unity checks. Details of the simplified methods are
given in the BS5950 Theory section.
Parameters
SIMP
Keyword
ELEM
Keyword to denote element list follows:
integer list
List of user element numbers (Integer).
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Usage
Optional for BS59 command data block.
Notes
1. By default the more rigorous checks will be carried out for all elements.
Examples
SIMP ELEM ALL
SIMP ELEM 20 TO 60
SIMP ELEM 10 15 20
3.60. SPEC
The SPEC command is used to specify which basic loadcases selected for reporting on CASE commands
and which basic loadcases referred to on CMBV or COMB commands originate from response spectrum
analysis and are to be subject to ‘automatic signed expansion procedures’ when stress checking to a
design code.
Parameters
SPEC
Keyword
integer list
List of response spectrum basic loadcases in the data, or ALL for all loadcases (Integer).
Usage
Optional - this command is only applicable for the following code checks:
AISC WSD ALLO
API WSD ALLO
API WSD NOMI
API WSD PUNC
API LRFD JOIN
API LRFD MEMB
Notes
1. This command is only required if ‘automatic signed expansion’ of response spectrum loadcases is required,
otherwise they may be treated as linear static with the omission of this command.
2. If omitted all basic loadcase are assumed to be linear static.
Examples
SPEC 1 7 19 206
SPEC ALL
SPEC 1 7 28 TO 99
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STUB
3.61. STRU
The STRU command is used to define the name of an existing structure within the current project for
which the results are to be processed in this run.
The STRU command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
STRU
Keyword
sname
Structure name identifying which existing structure is to be accessed from the current project, see PROJ
command. (Alphanumeric, four characters, the first character must be alphabetic).
Usage
Compulsory.
Notes
1. See also COMP command.
Examples
STRUCTURE SHIP
3.62. STUB
The STUB command is used to specify end stub diameter and wall thickness at both or either end of
TUBE elements, or other beam elements defined as having tubular cross-section.
Parameters
STUB
Keyword
END1, END2
Optional keywords.
value1, value3
End stub outside diameter of END1 and END2 respectively (Real).
value2, value4
End stub wall thickness at END1 and END2 respectively (Real)
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ELEM
Keyword to denote selection by element number.
GROU
Keyword to denote selection by element group number. Only applicable to an ANSYS Asas based analysis.
PROP
Keyword to denote selection by geometric property number.
integer list
List of user element numbers, group numbers or geometric property numbers (Integer).
Usage
Optional for tubular joint punching shear command data blocks.
Notes
1. Element definition of stub diameter and wall thickness overrides group definition, which in turn overrides
geometric property number definitions. See BEAMST Priority of Data Assignments (p. 56).
2. All tubular end diameters and wall thicknesses not redefined using the STUB command will default to
those of the analysis unless redefined via the DESI command.
3. See the introduction to the Command Reference section for details on the priority of assigning data.
Examples
STUB
STUB
STUB
STUB
STUB
0.702 0.052 ELEM 1 TO 16 24 99
END1 0.702 0.052 ELEM ALL
END2 0.762 0.064 GROUP 77 92
0.072 0.052 0.762 0.064 PROP 64 72
END1 0.072 0.052 END2 0.762 0.064 GROU 1 TO 9
3.63. SYST
The SYST command is used to define the amount of memory used for data by this run.
The SYST command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
SYST
Keyword
DATA AREA
Keywords
memory
Amount of memory (in 4 byte words) to be used by this run. Typical values are between 30000 and
1000000.
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TITLE
Usage
Optional.
Examples
SYSTEM DATA AREA 80000
3.64. TEXT
The TEXT command is used to define a line of text to be printed once only at the beginning of the
output. Several TEXT lines may be defined to give a fuller description of the current analysis on the
printed output.
The TEXT command is a preliminary command, and should only appear at the head of the BEAMST
data set.
Parameters
TEXT
Keyword
text
This line of text will be printed once, at the beginning of the output (Alphanumeric, up to 75 characters).
Usage Optional.
Examples
TEXT THIS EXAMPLE OF THE
TEXT TEXT COMMAND IS SPREAD
TEXT OVER THREE LINES
3.65. TITLE
The TITLE command is used to specify/redefine the global title which is printed at the top of each page
of the BEAMST output.
Parameters
TITLE
Keyword
title
New page title, up to 60 characters.
Usage
Optional.
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Notes
1. If omitted, the global title defaults to that defined on the TITLE command in the BEAMST preliminary
data.
2. A blank space must exist between TITLE and title.
3. The global title once redefined using the TITLE command remains as such until another TITLE command
is processed from the BEAMST command data block.
4. Any number of TITLE commands may be used.
Examples
TITLE Example Title Command - (CASE NO. 1 * 1.20)
3.66. TOPO
The TOPO command is used to define the elements and associated step and length information for all
elements to be processed in a stand-alone run.
Important
The TOPO command should be used only when running BEAMST in stand-alone mode.
Parameters
TOPO
Keyword
node1, node2
Node numbers at the element ends. If omitted then the program defaults to 1 and 2 node2 respectively
(Integer).
PRIS
Keyword to denote that this element is prismatic.
length
Physical length of the element (Real).
STEP
Keyword to denote that this element is stepped.
stpno
Step number - must form a sequence from 1 to the number of steps on the element (Integer).
stlen
Step length (Real).
ELEM
Keyword to denote that element number follows.
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TYPE
elno
User element number (Integer).
GROU
Keyword to denote that group number follows
grpno
Group number to be assigned to this element, if omitted then defaults to 0 (Integer).
Usage
Compulsory. All TOPO commands must be placed together immediately following the preliminary data
block.
Notes
1. Note that the TOPO data block must be terminated by an END data line.
2. For stepped beams stpno and stlen must be defined for every section of a stepped member. See example
below.
3. The group number specification is optional, but is often useful for simplifying the input of other data.
(e.g. YIEL data).
Examples
TOPO 1 2 PRIS 10. ELEM 20 GROU 1
TOPO 2 4 STEP 1 10. 2 20. 3 10. ELEM 30
3.67. TYPE
The TYPE command is used to specify joint type and joint brace member.
Parameters
TYPE
Keyword
node
Node number to which the brace connects to form the joint.
per
Percentage denoting that portion of the brace punching load that is carried by a joint of classification
type1, the remainder being carried by type2 (Integer).
type1, type2
Joint type classifications, as follows:
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K
K joints
T
T & Y joints
TY
T & Y joints
Y
T & Y joints
YT
T & Y joints
DT
Cross joints: Double-T joints
X
Cross joints: X joints
brace
User element number of the brace (Integer).
brace2
User element number of the second brace of a K joint or X joint (Integer).
This value is valid only for the following code checks:
API WSD JOIN
Used to identify 2nd member for geometry based K and X joint gap calculations.
DS449
Used to calculate mean brace diameter for gap/diameter ratios in K joint assessments.
NORSOK
Used to identify balancing member for K joint assessments.
value
Gap dimension for K joints or offset for X joints (Real).
CASE
Keyword to denote that loadcase numbers follow.
integer list
List of basic and/or combined user loadcase numbers (Integer).
ALL
Keyword to denote all loadcases.
DEFL
Keyword denoting that the defaults type classifications follow.
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ULCF
dtype1
Default joint (chord/brace pair) type for non “perpendicular” brace members (smaller included angle
between brace and chord is less than or equal to 80 degrees).
dtype2
Default joint type for “perpendicular” brace members (smaller included angle between brace and chord
is greater than 80 degrees). This value is optional, defaults to T.
Usage
Optional for K or T & Y joint punching shear and brace end fatigue command data blocks. Compulsory
for models containing cross joints that are to be processed in the current run, except for those being
assessed using the API WSD JOIN check. For the API WSD JOIN check a load dependant classification
will be carried out. In this case the axial load will determine the proportion of joint type for each brace
member for each loadcase. In this instance note 1 below does not apply and default values using TYPE
DEFL are not applicable.
Notes
1. In the absence of any TYPE command(s) at a joint, joints will automatically be classified as K or T & Y,
depending upon each brace-chord pair geometry.
2. If per is omitted, the joint is classified as 100% joint type1. If per is less than 100, type2 must be present.
3. All joint types not specified with the TYPE command default to those in the TYPE DEFL command. If a
TYPE DEFL command is not present joints are automatically classified. See the appropriate sections for
joint checks in the relevant codes of practice.
4. If the gap dimension is omitted the default value specified by the GAPD command is assumed. If the
GAPD command does not appear, or in the case of API WSD JOIN a second brace is not defined, a gap
of 2 inches is used.
5. All user loadcase numbers must be explicitly defined if the CASE keyword is employed. If not the
shorthand syntax ALL is permissible.
6. For X and K joints, separate type commands are required to fully define opposing braces.
Examples
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
TYPE
16 90 K TY 14 CASE 1 10
20 K 46 ALL
240 60 K X 17 CASE 1 4 10 12 19
68 40 DT Y 92 ALL
79 75 YT K 107 CASE 93
81 70 K X 15 100.0 ALL
DEFL Y T
3.68. ULCF
The ULCF command is used to specify the unbraced length of the compression flange used in calculations
for lateral buckling due to bending in allowable stress command data blocks or the unstiffened length
of cylinder between stiffening rings, diaphragms or end connections in hydrostatic collapse command
data blocks.
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Parameters
ULCF
Keyword
FACT
Keyword to denote that unbraced length is to be specified as factor of member length.
factor
Factor of element length (Real).
LENG
Keyword to denote that unbraced length is to be specified explicitly.
length
Unbraced length (Real).
ELEM
Keyword to denote that element numbers follow.
GROU
Keyword to denote that group numbers follow (only applicable to an ANSYS Asas based analysis.):
integer list
List of user element numbers or element group numbers (Integer).
Usage
Optional for all stress checks to design code command data blocks.
Notes
1. If neither FACT nor LENG is specified, then LENG is assumed by default.
2. A length of zero (0.0) can be provided to indicate that lateral and torsional buckling are to be restrained
for I beams when carrying out allowable stress checks to NS3472E.
3. If the ULCF command is omitted, the unbraced/unstiffened length is assumed equal to the member
length. Note that a member may consist of several beam elements.
4. For column buckling checks an UNBR command is also required.
Examples
ULCF 22.O ELEM 10 TO 20
ULCF FACT 0.7 GROUP 10 12 TO 19 49
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UNBR
3.69. UNBR
The UNBR command is used to specify the unbraced lengths y and z used in calculating slenderness
ratios K /r for column buckling calculations about each axis. With this command either unbraced lengths
can be specified or factors by which the actual member length must be multiplied.
Parameters
UNBR
Keyword
FACT
Keyword to denote that unbraced length is to be specified as factor of member length.
factor1, factor2
Factors of member length (Real).
LENG
Keyword to denote that unbraced length is to be specified explicitly.
length1, length2
Unbraced lengths (Real).
ELEM
Keyword to denote that element numbers follow.
GROU
Keyword to denote that group numbers follow (only applicable to an ANSYS Asas based analysis):
integer list
List of user element numbers or element group numbers (Integer).
Usage
Optional for AISC, API, BS59 , DS449 and NORS member checking command data blocks.
Notes
1. If neither FACT nor LENG is specified, then LENG is assumed by default.
2. If only one value is specified,
y
and
z
are both set to it; otherwise
y
is set to value1 and
z
to value2.
3. If the UNBR command is omitted unbraced lengths are assumed equal to member lengths. Note that a
member may consist of several beam elements.
4. For local buckling and hydrostatic checks a ULCF command is also required.
Examples
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BEAMST Command Reference
UNBR 22.O 15.O ELEM 1O1 1O6 112
UNBR FACT O.9 1.O ELEM 1O TO 15
UNBR LENG 33.O ELEM 59
3.70. UNIT
The UNIT command is used to define the units which have been used in the previous analysis and also
to define the units to be used to print the stress results.
Parameters
UNIT
Keyword
STRE
Keyword
Important
The STRE keyword is a preliminary option, and should only be present when the UNIT
command is used at the head of the BEAMST data set.
unitnm
Name of unit to be utilized (see Notes).
Usage
If units were not used in the previous analysis then this command is compulsory, otherwise it is optional.
Notes
1. By default, the analysis units used in the previous analysis will be used.
2. If analysis units were not defined for the previous analysis, the units used MUST be specified here. If
analysis units were defined for the previous analysis, they can be reconfirmed here but cannot be changed.
3. If it is required to print the results in different units from the analysis units, these units may be defined
with this command using the keyword STRE followed by the unit or units to be changed.
4. The units for printed results can also be defined on the PRIN command. If PRIN is used in addition to
UNIT STRE, the PRIN values will override the UNIT STRE values.
5. Only those output units which are required to be modified need to be specified, undefined terms will
default to analysis units. Valid unit names are as follows:
Length
124
METRE(S)
M
CENTIMETRE(S)
CM
MILLIMETRE(S)
MM
MICROMETRE(S)
MICM
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WAVE
Force
NANOMETRE(S)
NANM
FOOT, FEET
FT
INCH, INCHES
IN
NEWTON(S)
N
KILONEWTON(S)
KN
MEGANEWTON(S)
MN
TONNEFORCE(S)
TNEF
POUNDAL(S)
PDL
POUNDFORCE
LBF
KIP(S)
KIP
TONFORCE(S)
TONF
KGFORCE(S)
KGF
Examples
To define or reconfirm the analysis units:
UNIT N M
To change the length unit to millimetres for printed output:
UNIT STRE MM
3.71. WAVE
The WAVE command is used to specify Wave Height and Period for the calculation of wave induced
hydrostatic pressure head.
Parameters
WAVE
Keyword
value1
Wave Height (Real).
value2
Wave Period in seconds (Real).
Usage
Optional for hydrostatic collapse checks.
Notes
1. If omitted, the still water level is used for hydrostatic check (see ELEV command).
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BEAMST Command Reference
2. The unit of Wave Height must be identical with that specified on the current UNIT command.
Examples
WAVE 5.0 10.0
3.72. YIEL
The YIEL command is used to specify the yield stress to be used for each element, group or material
property in the requested report. This yield stress may be referenced to a particular step number within
the elements defined by the element, group or material property lists.
Parameters
YIEL
Keyword
value
The yield stress (Real).
STEP
Keyword to denote that step number follows.
stepno
Step number to which the yield stress is referenced (Integer).
ELEM
Keyword to denote that element numbers follow.
GROU
Keyword to denote that group numbers follow. Only applicable to an ANSYS Asas based analysis.
MATE
Keyword to denote that material numbers follow.
integer list
List of user element, group or material property numbers to be assigned this yield stress (Integer).
Usage
Compulsory for all stress checks to design code command data blocks.
Notes
1. The yield stress must be entered in the same units as defined by the current UNIT command.
2. If a step reference is given only that step for elements specified within the element list, group number
list or material property number list is assigned this yield stress.
Examples
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YIEL
YIELD 2.OE8 ELEM ALL
YIEL 20000.0 ELEM 75 TO 80
YIEL 4.137E5 STEP 3 ELEM 1 6 16 TO 94 197
YIELD 3.447E5 STEP 20 GROUP ALL
YIELD 20000.0 MATE 5 8
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127
128
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Chapter 4: BEAMST AISC Theory
The AISC command data block is used to request checking of members to the AISC WSD standard (Ref.
1) and AISC LRFD (Ref. 23). Currently tubular, I-shaped and hollow rectangular section types are supported.
Note, all the equations and formulae in this chapter assume units of Kips and Inches.
4.1. AISC Working Stress Design Allowable Member Stress Check (AISC
WSD ALLO)
This section discusses the following topics:
4.1.1. AISC WSD ALLO Overview
4.1.2. AISC WSD ALLO Unity Check Report
4.1.3. AISC WSD ALLO Nomenclature
4.1.4. AISC WSD Allowable Stresses and Unity Checks
4.1.5. Spectral Loadcases and ‘Automatic Signed Expansion Procedures’
4.1.1. AISC WSD ALLO Overview
The AISC WSD ALLO command set is used to request that extreme fiber allowable stresses be calculated
and unity checks be performed according to the AISC design specification (Ref. 1).
The AISC WSD specification is written in terms of member yield strengths, so a YIELd command must
be used to specify the yield strength. The units of the yield strength must be those of the UNIT command
(BEAMST Command Reference (p. 51)).
Members may be selected for processing by elements and/or groups. The member section types must
be specified (if not specified in the structural analysis) using DESI commands. Further commands are
available for defining structural characteristics of the members (EFFE, UNBR and ULCF ) and for specifying
members that are classified as ‘secondary’ (SECO).
Loadcases from the preceding structural analysis may be selected for processing using the CASE command
and/or new loadcases formed from combinations of existing loadcases using the COMB and CMBV
commands. The AISC permitted one third increase in allowable stresses for wind or seismic loading may
be requested on a loadcase basis using the EXTR command.
The SECT command may be used to define intermediate points along a member at which member
forces are to be evaluated, checked and reported. These are in addition to results automatically printed
at the member end points and positions of any step change in cross-section properties. For the code
checks it is necessary to ensure the maximum acting bending moment and stresses are evaluated. Since
this may not occur at one of the ‘selected’ locations, BEAMST has a SEARch command which causes the
moments and stresses to be evaluated at every L/4 and L/6 (L = beam length) for prismatic and stepped
beams respectively. These extra locations are in addition to those selected and the results at these
locations are only presented if they give the maximum moments or stresses.
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129
BEAMST AISC Theory
The selection of output reports is made using the PRIN command with the appropriate parameters for
the required reports. The PRIN command is also used to request the various summary reports available
and to set exceedence values for the unity checks. Four summary reports are available:
Summary report 1 is requested with the PRIN SUM1 command and gives the highest local buckling,
global buckling and yield unity check values for each element.
Summary report 2 is requested with the PRIN SUM2 command and gives the highest buckle check and
all unity checks at the section with the highest yield combined stress unity check for each element.
Summary report 3 is requested with the PRIN SUM3 command and consists of the highest unity check
for each selected loadcase for each element selected.
Summary report 4 is requested with the PRIN SUM4 command and provides the three worst unity checks
for each selected group, together with the distribution of unity check values. The distribution provides
information on the number of unity checks exceeding an upper limit (default 1.0), less than a lower
limit (default 0.5), and the number in the mid-range.
A complete list of the command set available for the AISC WSD code check is given in Table 4.1: AISC
WSD ALLO Commands (p. 130) below. An example data file is given in Example 4.1: Example of AISC
WSD ALLO data file (p. 131).
Table 4.1: AISC WSD ALLO Commands
Command
Description
Usage
AISC WSD
ALLO
AISC WSD ALLOwable stress header command
C
UNIT
Units of length and force
C
1
YIEL
Yield stress
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SECO
Secondary members
SEAR
Search other sections in addition to those
requested on the SECT command for maximum forces and stresses
DESI
Defines design section properties
C
3
PROF
Section profiles for use in design
EFFE
Effective lengths/factors
CB
Pure bending Cb coefficient
CMY/CMZ
Amplification reduction factors Cmy/Cmz
UNBR
Unbraced lengths of element
ULCF
Unbraced length of compression flange
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Command
Description
Usage
Note
CASE
Basic loadcases to be reported
C
4
COMB
Define a combined loadcase for processing
C
4
CMBV
Define a combined loadcase for processing
C
4
SELE
Select/redefine a combined/basic loadcase
title
SPEC
RENU
Basic loadcases from response spectrum
analysis
EXTR
Renumber a ‘basic loadcase’
QUAK
Loadcases allowing 33% overstress
Loadcases with earthquake permitted overstress
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. Compulsory for non-tubular elements unless sections have been used in the preceding analyses for all
elements to be processed.
4. At least one CASE, CMBV or COMB command must be included.
Example 4.1: Example of AISC WSD ALLO data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE DECA
OPTION GOON
END
AISC WSD ED9 ALLO
*
* Select all elements using the GROUP command except
* elements 991 and 992 - dummy elements
*
GROUP ALL
NOT ELEMENT 991 992
UNIT KN M
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BEAMST AISC Theory
*
* Define section properties for some elements that
* used areas and inertia values in the ASAS run
*
UNITS MM
DESI RHS 900.0 400.0 40.0 ELEMENT 851 TO 854 861
: 931 TO 942
UNITS M
*
* Examine two load cases including jacket loading
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Indicate that these loadcases are extreme events
*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main deck beams use effective length
* coefficient of 1.0
* Deck columns use effective length coeff of 1.2
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFE 0.8 ELEM 851 To 854
EFFE 1.0 GROU ALL
*
* Unbraced lengths need redefining
* assumes no lateral restraint from deck plating
*
UNBR FACT 1.0 2.0 ELEM 701 704
UNBR FACT 2.0 1.0 ELEM 706 707
UNBR FACT 2.0 ELEM 702 703
UNBR LENG 4.875 19.5 ELEM 711 713
UNBR LENG 9.75 19.5 ELEM 712
*
* Override program computed moment amplification RF
*
CMZ 0.85 ELEM 711 712 713
CMZ 0.85 ELEM 701 TO 704
CMY 0.85 ELEM 702 703
CMY 0.85 ELEM 706 707
*
* Check mid-span and quarter point sections
*
SECT 0.25 0.5 0.75 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 SUM2 SUM3 SUM4 BOTH
END
STOP
4.1.2. AISC WSD ALLO Unity Check Report
The detailed unity check report is presented on an element by element basis. The header line displays
the element number, the associated node numbers, the element group number and the units in use.
The results are printed for each of the selected positions (or sections) on the element for each loadcase
in turn. The first columns of the report define the loadcase, section number and position as a ratio of
the elements length.
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
The allowable stresses for axial, shear and bending (in local Y and Z axes) stresses are presented in the
next columns of the report. These are preceded by an alphanumeric descriptor (CODE) that indicates
the derivation of each of the allowable stresses. These descriptors are of the form:
T.XVYZ or C.XVYZ
T or C defines whether the member is in tension or compression, XVYZ are individual alpha codes which
relate to the axial(X), shear(V), and bending(Y,Z) allowable stresses. These alpha codes specify the design
code clause or equation used to evaluate the allowable stresses and are defined in Table 4.2: Allowable
Stress Alphabetic Codes (p. 133).
Table 4.2: Allowable Stress Alphabetic Codes
Stress
Code
Clause
Description
X
A
B7
axial tension - B7 satisfied
B
B7
axial tension - B7 violated
C
(E2-1)
axial compression - E2 satisfied
D
(A-B5-9)
axial compression - E2 violated
E
(A-B5-12)
axial compression - kL/r > Cc'
G
(B5.2.b)
axial compression, tubular section, Appendix
Bcontrolling
B
(F4-2)
shear buckle
Y
(F4-1)
shear yield
V
U
user defined
Y
A
(F3-1)
Major - I, H, Boxes/Major and Minor - Tube
Z
B
(F2-1)
Minor - I, H, Boxes and Solid Rectangular
Sections
D
(F1-4)
E
(F2-3)
F
(F3-3)
I
(A-B5-3)
J
(A-B5-4)
K
(A-B5-7)
L
(A-B5-9)
M
(AISC 1.5.1.4.5(1))
N
(F1.3)
O
(F1-6)
Major - I, H
Minor - I, H
Major and Minor - Boxes
Major and Minor - I, H
Major and Minor - I, H
Major and Minor - Boxes
Major and Minor - I, H
Major and Minor - I, H
Major - I, H
Major - I, H
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Stress
Code
Clause
Description
P
(F1-7)
Major - I, H
Q
(F1-8)
Major - I, H
R
(F1-5)
Major - Solid Rectangular Section
S
(E2-1) (C-F3-1)
Major - Boxes
T
(E2-2) (C-F3-1)
Major - Boxes
For example, the unity check CODE combination
C.CYCC
indicates that the member is in compression and that the following clause/equations were used to derive
the allowable stresses:
• Axial - C = (E2-1) axial compression - E2 satisfied
• Shear - Y = (F4-1) shear yield
• Bending Y - B = (F2-1) Minor - I, H, Boxes and Solid Rectangular Sections
• Bending Z - A = (F3-1) Major - I and H
The last two characters are always the same for tubular members.
The final column of the table, headed Messages, flags all lines of results where any of the checks have
failed. These messages may be summarized as follows:
FAIL
Code check failure for this member
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
SLRF
Slenderness ratio greater than 200 for a compression member
SLRW
Slenderness ratio greater than 300 for a tension member
SHYF
Shear yielding failure
DTRF
D/t ratio exceeds 13000/fy (ksi units)
WBIC
Web plate ineffective in axial compression
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
FLIC
Flange plate ineffective in axial compression
FLIB
Flange plate ineffective in major axis bending
PEWB
Partially effective web(s), major axis bending allowable reduced
PEFL
Partially effective flange(s), minor axis bending allowable reduced
WBSF
Flange buckling requiring web stiffeners
SHBF
Shear buckling failure
WBHP
Web requires stiffening
CONS
Unbraced length of compression flange less than element length, conservative assumption for CB, CM
HAND
Unbraced length of compression flange exceeds element length, manual check required, CB, CM defaulted
4.1.3. AISC WSD ALLO Nomenclature
AISC WSD ALLO uses the following nomenclature:
4.1.3.1. AISC WSD ALLO Nomenclature - Dimensional
4.1.3.2. AISC WSD ALLO Nomenclature - Acting Stresses
4.1.3.3. AISC WSD ALLO Nomenclature - Allowable Stresses
4.1.3.1. AISC WSD ALLO Nomenclature - Dimensional
(a) Rolled Sections
(b) Welded Sections
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BEAMST AISC Theory
D
Tube outside diameter.
t
Thickness.
b
Actual width of box flange plates, I flange effective width, solid rectangular overall width.
be
Effective width of stiffened compression elements.
d
Depth of I, box and solid rectangular sections.
h
Clear distance between flanges.
he
Effective depth of stiffened compression web elements.
tf
flange plate thickness.
tw
Web plate thickness.
k, kw, kz
Effective length factors. Subscript refers to the associated axis. No subscript refers to either axis as appropriate.
L
Unbraced member length about either axis as appropriate.
LULCF
Unstiffened length of the compression flange.
rT
Torsional radius of gyration.
r, ry, rz
Radii of gyration. Subscript refers to the associated axis. No subscript refers to either axis as appropriate.
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Aw
Cross-sectional area of the web(s).
Af
Cross-sectional area of the flange(s).
4.1.3.2. AISC WSD ALLO Nomenclature - Acting Stresses
fa
Computed axial stress.
fb
Resultant bending stress for tubes.
fb, fby, fbz
Computed bending stresses for non-tubulars. Subscript refers to the associated axis. No subscript refers
to either axis as appropriate.
fvy, fvz
Shear stresses. Subscript refers to the associated axis.
fvmax
Shear stress for tube.
4.1.3.3. AISC WSD ALLO Nomenclature - Allowable Stresses
Cb
Bending coefficient.
Cmy, Cmz
Amplification reduction factors for y and z axis buckle checks.
E
Young’s modulus.
Fa
Axial compression stress.
Fbcy, Fbcz
Bending stress for compression. The last subscript refers to the associated axis.
Fbty, Fbtz
Bending stress for tension. The last subscript refers to the associated axis.
Fe
Euler buckling stress.
Ft
Axial tension stress.
Fv, Fvy, Fvz
Shear stress. Second subscript refers to the associated axis.
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fy
Yield stress.
UCax
Axial unity check (tension or compression).
UCvy, UCvz
Shear unity check.
UCvmax
Shear resultant unity check for tubes.
UCby, UCbz
Pure bending unity check.
UCB
Combined axial compression and bending buckle check.
UCY
Combined axial and bending yield check.
UCCSR
Upper bound member buckling check.
4.1.4. AISC WSD Allowable Stresses and Unity Checks
The equations defined in the following section assume units of Kips and inches.
4.1.4.1. AISC WSD Allowable Stress Increase
Working stress design codes permit allowable stresses to be increased above those appropriate to Ordinary conditions for other conditions. The percentage increase in allowable stresses to be applied to
the allowable stresses quoted herein for different loadcase types are:
Type
Axial/Bending
Shear
Ordinary
0.0
0.0
Extreme
33.33
33.33
Earthquake
33.33
33.33
4.1.4.2. AISC WSD ALLO - Axial Tension Checks
Clause/(Eqn)
Commentary
Code
Message
Limiting Slenderness Ratio
B7
Allowable stress
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
4.1.4.3. AISC WSD ALLO - Axial Compression Checks
Clause/(Eqn)
Commentary
Code Message
Limiting Slenderness Ratio
B7
Allowable stress
Web
Flange
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Code Message
Web
Flange
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
4.1.4.4. AISC WSD ALLO - Bending Checks
Clause/(Eqn)
Commentary
Code Message
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Clause/(Eqn)
Commentary
Code Message
Major Axis
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
Minor Axis
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BEAMST AISC Theory
Clause/(Eqn)
144
Commentary
Code Message
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
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Clause/(Eqn)
Commentary
Code Message
4.1.4.5. AISC WSD ALLO - Shear Checks
Clause/(Eqn)
Commentary
Code Message
Y
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
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Clause/(Eqn)
Commentary
Code Message
4.1.4.6. AISC WSD ALLO - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
Shear
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
Pure Bending
F
4.1.4.7. AISC WSD ALLO - Combined Stress Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial compression and bending buckle check
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Clause/(Eqn)
Commentary
Code Message
Axial tension and bending buckle check
Axial tension and bending buckle check
4.1.4.8. AISC WSD ALLO - Combined Axial and Bending Unity Check
Clause/(Eqn)
Commentary
Code Message
Axial compression
Axial tension
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
Axial tension
4.1.4.9. AISC WSD ALLO - Bending Coefficient, Cb
Clause/(Eqn)
Commentary
Message
CONS
HAND
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Clause/(Eqn)
Commentary
Message
4.1.4.10. AISC WSD ALLO - Amplification Reduction Factors, Cmy, Cmz
Clause/(Eqn)
Commentary
Message
CONS
HAND
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
Clause/(Eqn)
Commentary
Message
4.1.5. Spectral Loadcases and ‘Automatic Signed Expansion Procedures’
In response spectrum analysis using modal superposition (Ref. 12) the structure displacements and
forces calculated represent estimated maxima and are, in general, unsigned (positive).
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For the purpose of checking members to AISC WSD, a series of worst static-spectral possible loadcases
must be generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depend upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition.
4.1.5.1. Torsional Effects
The maximum torsional spectral load contribution at each beam section position is deduced in a similar
manner to the axial load contribution in 4.1.5.2.
4.1.5.2. Axial Unity Check and the Axial Component of Combined Stress Buckle and
Yield Unity Checks
The maximum axial spectral load contribution at each beam section position is calculated by assuming
that the spectral axial load distribution is linear with both member end loads having the same sign.
The sign adopted for these member spectral end loads is normally assumed to be of the same sign as
the static axial load (if it exists). In cases where the static loadcase is tensile it is possible that reversing
the sign of the spectral case may produce a net compressive load and, hence, a more onerous utilization
(since buckling may become a problem). Under these conditions, the checks are repeated with the
spectral axial stresses reversed with respect to the static case, and the combination producing the
highest utilization of both conditions is reported. The sign adopted may be ascertained from the utilization code reported.
As in all checks performed by BEAMST, zero axial stress is treated as compressive (-ve sign, ASAS convention).
4.1.5.3. Local Axes Shear Unity Checks and Maximum Shear Unity Check for Tubular
Sections
In order to be able to generate mid-member stresses an equivalent member spectral loading is required.
BEAMST assumes that the spectral loading consists of a linearly varying inertia loading on the member
acting in a rigid fashion (that is, the load consists of that due to pure translation and rotation of the
member). This inertia loading is calculated by ‘balancing’ it against the member signed spectral end
forces (shears and moments).
For each local bending plane there are sixteen unique signed spectral end force (shears and moments)
expansions/cases of which eight are symmetric, but of opposite sign, to the remaining eight. Each of
these sixteen signed spectral expansions is denoted by a single alphabetic letter code in BEAMST in
the range A-P as shown in Table 4.3: Automatic Signed Spectral Expansion Codes for Member Checks
and the Respective Signs Applied for Bending in the Local Y-Y/Z-Z Planes (p. 156). For spectral loadcases
only eight of the sixteen possible expansions need theoretically be considered but for static-spectral
summations all sixteen have to be taken into account.
The Shear Unity Checks are maximized by adopting the static-spectral signed expansion which maximizes
the total acting shear at each beam section position. For tubular sections the combination of staticspectral expansions which maximizes the resultant acting shear on the cross section and the Maximum
Shear Unity Check.
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AISC Working Stress Design Allowable Member Stress Check (AISC WSD ALLO)
For a linearly varying inertia load it can be deduced a priori that the following spectral expansions are
critical for the Shear Unity Checks for static-spectral summation.
Beam section position (α)
Local axes spectral expansion
0 < α < 1/3
E or L
1/3 < α < 2/3
D or M
2/3 < α < 1
B or O
4.1.5.4. Local Axes Pure Bending Unity Checks and Bending Components of Combined
Stresses Yield Unity Check
For bending unity checks and unity check bending components it is necessary to determine the spectral
expansion which maximizes the ratio of acting to allowable stress as opposed to simply maximizing
the acting bending stress. In general this is necessary because the bending allowable may be a function
of Cb which itself is a function of the signs and relative magnitudes of the member total end forces.
BEAMST investigates each of the sixteen signed spectral expansions shown in Table 4.3: Automatic
Signed Spectral Expansion Codes for Member Checks and the Respective Signs Applied for Bending in
the Local Y-Y/Z-Z Planes (p. 156) for both of the local axes bending planes for each beam section position
being considered and reports the critical expansions at each section. For tubular sections being checked
to AISC WSD where it is necessary to calculate bending resultants at each beam section the spectral
expansions which maximize the ratio of local axes bending stress to allowable are determined (as these
local axes acting bending stresses are the ones which also maximize the acting bending resultants and
hence maximize the yield unity check components).
For static-spectral summation it is theoretically necessary to investigate all sixteen spectral expansions
for the worst cases but for loadcases composed of expanded spectral contributions only, the following
generalizations can be made:
1. The acting bending stress at each beam section position is maximized by adopting the spectral expansion
defined by end moments of the same sign and end shears of opposite signs.
2. Where the allowable stress is a function of Cb, the allowable will be minimized by adopting the expansion
with spectral end moments of the same sign as this minimizes Cb.
These two generalizations taken together imply spectral expansions A or P (Table 4.3: Automatic Signed
Spectral Expansion Codes for Member Checks and the Respective Signs Applied for Bending in the
Local Y-Y/Z-Z Planes (p. 156))
4.1.5.5. Unity Check Report for Shear, Pure Bending and Yield Unity Checks
The Unity Check Report for a spectral or a static-spectral summation comprises four separate reports:
1. Highest Shear Unity Checks
2. Highest Pure Bending Unity Checks
3. Highest Yield Unity Checks
4. Highest Buckle Unity Checks
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The unity checks of direct interest to the user when checking against a design code are the shear checks
in the Highest Shear Unity Checks, the pure bend checks in the Highest Pure Bending Unity Checks etc.
For the Highest Shear, Pure Bending and Yield Reports, the worst unity check at each beam section
position is reported together with the spectral expansions in the local Y and Z which maximize the respective checks (as described in Torsional Effects, Axial Unity Check and the Axial Component of Combined Stress Buckle and Yield Unity Checks, Local Axes Shear Unity Checks and Maximum Shear Unity
Check for Tubular Sections and Local Axes Pure Bending Unity Checks and Bending Components of
Combined Stresses Yield Unity Check above) appended to the loadcase number. In addition to the unity
checks of direct interest in each report all remaining unity checks are calculated for the spectral expansions quoted and are reported. This allows users to obtain an overall picture of stress state in the beam
at the section under consideration for the spectral expansions cited. The combined buckle unity checks
in these reports and the Highest Buckle Unity Check Report are explained in AISC Combined Stress
Buckle Unity Check below.
4.1.5.6. AISC Combined Stress Buckle Unity Check
As for the pure bending and yield unity check it is necessary to determine which spectral expansions
maximize the bending components of the buckle unity check defined by ratio of ‘equivalent uniform
bending’ stress to minimum allowable. This is necessary because the amplification-reduction factor Cm
used to convert maximum acting bending stress to an equivalent uniform bending stress is a function
of the signs and relative magnitudes of the member total end forces (moments).
BEAMST investigates all sixteen spectral expansions determining for each expansion the maximum
bending stress and minimum allowable stress occurring anywhere along the beam and the buckle unity
check bending component for the bending plane being considered. Over all sixteen expansions, those
which maximize the bending components in each of the local bending planes are used in the final
buckle check and are reported in the Highest Buckle Unity Check Report.
Table 4.3: Automatic Signed Spectral Expansion Codes for Member Checks and the Respective
Signs Applied for Bending in the Local Y-Y/Z-Z Planes
Spectral Expansion
End1
Shear
End1
Moment
End2
Shear
End2
Moment
A
+
+
-
+
B
+
+
-
-
C
+
+
+
+
D
+
+
+
-
E
+
-
-
+
F
+
-
-
-
G
+
-
+
+
H
+
-
+
-
I
-
+
-
+
J
-
+
-
-
K
-
+
+
+
L
-
+
+
-
M
-
-
-
+
N
-
-
-
-
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Spectral Expansion
End1
Shear
End1
Moment
End2
Shear
End2
Moment
O
-
-
+
+
P
-
-
+
-
Note
1. Beam end spectral torque signs are chosen to be identical with their respective static components in static-spectral loadcases.
2. Beam end spectral torque signs adopted for evaluation of spectral stresses at intermediate
beam section positions are chosen to be identical with their respective static stress components
at the section under consideration.
4.2. AISC Load and Resistance Factor Design Member Check (AISC LRFD
MEMB)
This section discusses the following topics:
4.2.1. AISC LRFD MEMB Overview
4.2.2. AISC LRFD Unity Check Report
4.2.3. AISC LRFD MEMB Nomenclature
4.2.4. AISC LRFD MEMBER CHECKS
4.2.5. AISC LRFD MEMBER CHECKS - 3rd Edition
4.2.1. AISC LRFD MEMB Overview
The AISC LRFD MEMB header command in BEAMST is used to request member stress checks to AISC
LRFD design recommendations, second and third editions (Ref. 23, Ref. 25), for tubular, I-shaped and
hollow rectangular section types.
The AISC specification is written in terms of member yield strengths, so a YIELd command must be used
to specify the yield strength.
Members may be selected for processing by elements and/or groups. The member section dimensions
must be specified (if not specified in the structural analysis) using DESI commands. Further commands
are available for defining topological characteristics of the members (EFFE, UNBR and ULCF) and specifying members that are classified as ‘secondary’ (SECO).
The SECT command may be used to define intermediate points along a member at which member
forces are to be evaluated, checked and reported. These are in addition to results automatically printed
at the member end points and positions of any step change in cross-section properties. Alternatively
the SEARch command may be used which requests that moments and stresses are to be evaluated at
specified locations along the beam but to be reported only if they give a maximum force, stress or
utilization. These extra locations are in addition to those selected using the SECT command.
The AISC LRFD standard utilizes limit state checks with resistance coefficients to achieve the desired
level of safety. In keeping with this principle, applied loads must be multiplied by appropriate factors,
as defined in the code of practice (Section C, Loads), to develop the design load case combinations
necessary for processing. Where non-linear pile analysis is undertaken (using SPLINTER) the design loads
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must be applied to the pile model to account for the increased non-linearity this introduces. In situations
where a non-linear pile analysis has not been carried out, the design loads may be produced using the
COMB or CMBV commands utilizing the required load factors.
The selection of output reports is made using the PRIN command with the appropriate parameters for
the required reports. The PRIN command is also used to request the various summary reports available.
Two summary reports are available:
Summary report 1 is requested with the PRIN SUM1 subcommand and details the loadcase producing
the highest unity check value for each element.
Summary report 3 is requested with the PRIN SUM3 subcommand and consists of the highest unity
check for each selected loadcase for each element selected.
A complete list of the command set available for the AISC LRFD MEMB code checks is given in
Table 4.4: AISC LRFD MEMB Commands (p. 158) below and described in detail in BEAMST Command
Reference (p. 51). An example data file is given in Example 4.2: Example of AISC LRFD MEMB data
file (p. 159).
Table 4.4: AISC LRFD MEMB Commands
Command
Description
Usage
AISC LRFD
MEMB
AISC allowable stress header command
C
UNIT
Units of length and force
C
1
YIEL
Yield stress
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SEAR
Search other sections in addition to those
requested on the SECT command for maximum forces and stresses
C
3
C
4
SECO
Note
Secondary members
DESI
Defines design section properties
PROF
Section profiles for use in design
EFFE
Effective lengths/factors
CB
Pure bending Cb coefficient
CMY/CMZ
Amplification reduction factors Cmy/Cmz
UNBR
Unbraced lengths of element
ULCF
Unbraced length of compression flange
CASE
Basic loadcases to be reported
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Command
Description
Usage
Note
COMB
Define a combined loadcase for processing
C
4
CMBV
Define a combined loadcase for processing
C
4
SELE
Select/redefine a combined/basic loadcase
title
SPEC
RENU
Basic loadcases from response spectrum
analysis
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. Compulsory for non-tubular elements unless sections have been used in the preceding analyses for all
elements to be processed.
4. At least one CASE, CMBV or COMB command must be included.
Example 4.2: Example of AISC LRFD MEMB data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE DECA
OPTION GOON
END
AISC LRFD ED2 MEMB
*
* Select all elements using the GROUP command except
* elements 991 and 992 - dummy elements
*
GROUP ALL
NOT ELEMENT 991 992
UNIT KN M
*
* Define section properties for some elements that
* used areas and inertia values in the ASAS run
*
UNITS MM
DESI RHS 900.0 400.0 40.0 ELEMENT 851 TO 854 861
: 931 TO 942
UNITS M
*
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* Examine two load cases including jacket loading
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.35 1 1.1 3 1.1 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.35 2 1.1 3 1.1 4
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main deck beams use effective length
* coefficient of 1.0
* Deck columns use effective length coeff of 1.2
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFE 0.8 ELEM 851 To 854
EFFE 1.0 GROU ALL
*
* Unbraced lengths need redefining
* assumes no lateral restraint from deck plating
*
UNBR FACT 1.0 2.0 ELEM 701 704
UNBR FACT 2.0 1.0 ELEM 706 707
UNBR FACT 2.0 ELEM 702 703
UNBR LENG 4.875 19.5 ELEM 711 713
UNBR LENG 9.75 19.5 ELEM 712
*
* Override program computed moment amplification RF
*
CMZ 0.85 ELEM 711 712 713
CMZ 0.85 ELEM 701 TO 704
CMY 0.85 ELEM 702 703
CMY 0.85 ELEM 706 707
*
* Check mid-span and quarter point sections
*
SECT 0.25 0.5 0.75 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 SUM3
BOTH
END
STOP
4.2.2. AISC LRFD Unity Check Report
The detailed unity check report is presented on an element by element basis. The header line displays
the element number, the associated node numbers, the element group number and the units in use.
The results are printed for each of the selected positions (or sections) on the element for each loadcase
in turn. The first columns of the report define the loadcase, section number and position as a ratio of
the elements length together with the section dimensions, slenderness ratios and the moment amplification reduction factors, cmy and cmz.
Following the section information is an alphanumeric descriptor (CODE) that indicates the derivation
of each of the design strengths that have been computed for this section. These descriptors are of the
form:
T.XVYZ or C.XVYZ
T or C defines whether the member is in tension or compression, XVYZ are individual alpha codes which
relate to the axial(X), shear(V), and bending(Y,Z) design strengths. These alpha codes specify the design
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code clause or equation used to evaluate the design strengths and are defined in Table 4.5: Strength
Alphabetic Codes (p. 161).
Table 4.5: Strength Alphabetic Codes
Stress
Code
Clause
Description
X
A
B7
axial tension - B7 satisfied
B
B7
axial tension - B7 violated
C
(E2-2)
axial compression - Fcr indeterminate (Qa or Qs <
0)
D
(E2-3)
axial compression
E
V
axial compression
A
(F2-1)
shear yield
B
(F2-2)
shear buckle - FBI, WF, BOX, RHS
C
(F2-3)
elastic buckling stress - FBI, WF, BOX, RHS
Y
A
(A-F1-1)
Major - FBI, WF, BOX, RHS LTB
Z
B
(A-F1-2)
Major - FBI, WF, BOX, RHS LTB
C
(A-F1-4)
Major - FBI, WF, BOX, RHS LTB
D
(A-F1-1)
Major - FBI, WF, BOX, RHS FLB, TUB
E
(A-F1-3)
Major - FBI, WF, BOX, RHS FLB, TUB
F
(A-F1-4)
Major - FBI, WF, BOX, RHS FLB, TUB
G
(A-F1-1)
Major - FBI, WF, BOX, RHS WLB
H
(A-F1-3)
Major - FBI, WF, BOX, RHS WLB
J
(A-G2-1)
Major - FBI, WF, BOX, RHS Slender web tension
flange yield
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Stress
Code
Clause
Description
K
(A-G2-2)
Major - FBI, WF, BOX, RHS Slender web flange
local buckling
L
(A-F1-1)
Minor - FBI, WF, BOX, RHS
M
(A-F1-3)
Minor - FBI, WF, BOX, RHS
N
(A-F1-4)
Minor - FBI, WF, BOX, RHS
For example, the unity check CODE combination
C.DALA
indicates that the member is in compression and that the following clause/equations were used to derive
the allowable stresses:
• Axial - D = (E2-1) axial compression - (E2-2) satisfied
• Shear - A = (F2-1) shear yield
• Bending Y - L = (A-F1-3) Minor - FBI, WF, BOX, RHS
• Bending Z - A = (A-F1-1) Major - FBI, WF, BOX, RHS Lateral Torsional Buckle
The next two columns present the acting axial force, shear and bending moments pertaining to the
given loadcase, and these are followed by the nominal strengths and associated parameters for axial,
shear and bending loads and their respective utilizations.
The final column of the table, headed Messages, flags all lines of results where any of the checks have
failed. These messages may be summarized as follows:
FAIL
Member has a utilization exceeding unity or fails parameter limits (flagged with THKF, DTRF, SLRF).
PNT9
Unity check value exceeds 0.9
SLRF
Slenderness ratio greater than limiting value.
DTRF
D/t ratio exceeds 13000/fy (ksi units).
SHYF
Shear yielding failure.
SHBF
Shear buckling failure.
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HOVT
Web requires stiffening.
WBIC
Reduced web width calculation is required, this is not currently undertaken by the program.
HAND
Member is part of sway frame (k > 1.0). Manual check required for combined interaction check.
4.2.3. AISC LRFD MEMB Nomenclature
4.2.3.1. AISC LRFD MEMB Nomenclature - Definition of Symbols
(a) Rolled Sections
(b) Welded Sections
4.2.3.2. AISC LRFD MEMB Nomenclature - Dimensional
Ag
Gross cross sectional area
Aw
Area of web
Ay, Az
Shear area for y and z axis
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d
Full nominal depth of rolled or fabricated sections
b
Actual width of box flange plates, I flange effective width
h
Clear distance between flanges
hc
Assumed web depth for stability
D
Tube outer diameter
t
Tube thickness or thickness of rolled hollow section
tw
Web plate thickness
tf
Flange plate thickness
J
Torsion constant
Iy, Iz
Moment of inertia about y and z axis
Zy, Zz
Plastic modulus about y and z axis
Sy, Sz
Elastic section modulus about y and z axis
k, ky, kz
Effective length factors. Subscript refers to the associated axis. No subscript refers to either axis, as appropriate
L, Ly, Lz
Unbraced member length. Subscript refers to the associated axis. No subscript refers to either axis, as
appropriate
LULCF
Unstiffened length of the compression flange
r, ry, rz
Radii of gyration. Subscript refers to the associated axis. No subscript refers to either axis, as appropriate
rT
Torsional radius of gyration
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4.2.3.3. AISC LRFD MEMB Nomenclature - Acting Forces and Stresses
fa
Axial force
fby, fbz
Bending moment about y and z axis
fvy, fvz
Shear force for y and z axis
Fa
Axial stress
4.2.3.4. AISC LRFD MEMB Nomenclature - Strengths and Utilizations
Fey, Fez
Euler strength for y and z axis
Pn
Nominal axial strength
Mny, Mnz
Nominal flexural strength about y and z axis
Vy, Vz
Nominal shear strength for y and z axis
Mr
Limiting buckling moment
Mp
Plastic bending moment
Fcr
Critical stress
UCax
Axial unity check (tension or compression)
UCvy, UCvz
Shear unity check for y and z axis
UCby, UCbz
Pure bending unity check about y and z axis
UCcb
Combined axial and bending interaction check
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4.2.3.5. AISC LRFD MEMB Nomenclature - Parameters
E
Young's modulus
G
Shear Modulus
Cb
Bending coefficient
Cmy, Cmz
Amplification reduction factors for y and z axis
Fr
Compressive residual stress in flange = 10 ksi for rolled sections, 16.5 ksi for welded sections
Fy
Yield stress
Qa
Reduction factor for slender stiffened compression elements
Qs
Reduction factor for slender unstiffened compression elements
Q
Full reduction factor for slender compression elements
øc
Resistance factor for axial compression
øt
Resistance factor for axial tension
øb
Resistance factor for bending
øv
Resistance factor for shear
4.2.4. AISC LRFD MEMBER CHECKS
The equations defined in the following section assume units of Kips and inches.
4.2.4.1. AISC LRFD - Partial Coefficients
Clause/(Eqn)
Commentary
Code Message
Resistance factors
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Load coefficients
BEAMST assumes the appropriate factors have
already been applied by the user.
4.2.4.2. AISC LRFD - Nominal Axial Tension Strength
Clause/(Eqn)
Commentary
Code Message
Yielding on gross section
Limiting slenderness ratio
4.2.4.3. AISC LRFD - Nominal Axial Compressive Strength
Clause/(Eqn)
Commentary
Code Message
Limiting slenderness ratio
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Clause/(Eqn)
Commentary
Code Message
Web
Rolled section flange
Fabricated section flange
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Clause/(Eqn)
Commentary
Code Message
Web
If rolled hollow section or constant thickness
box
If fabricated box with different thickness
plates
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Clause/(Eqn)
Commentary
Code Message
Flange
Column slenderness parameter
Critical stress
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Nominal strength
4.2.4.4. AISC LRFD - Bending Strength
Clause/(Eqn)
Commentary
Code Message
Compressive flange residual stress
4.2.4.5. AISC LRFD - Major Axis Bending Strength
Clause/(Eqn)
Commentary
Code Message
Plastic capacity
The nominal flexural strength, Mn, is the lowest
value obtained according to the limit states of:
Lateral Torsional Buckling, Flange Local Buckling,
Web Local Buckling
Lateral Torsional Buckling
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Code Message
Non compact limit
Compact section
Non compact section
Slender section
Flange local buckling
172
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Compact section
Non compact section
Slender section
Web local buckling
Compact section
Non compact section
Slender section
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Code Message
4.2.4.6. AISC LRFD - Slender web
Clause/(Eqn)
Commentary
Code Message
Tension flange yield
Flange local buckling
Fcr is computed as follows for the limit states of
lateral torsional buckling and flange local buckling and the lower value used.
Lateral torsional buckling
Flange local buckling
174
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Critical stress Fcr
4.2.4.7. AISC LRFD - Minor Axis Bending Strength
Clause/(Eqn)
Commentary
Code Message
Flange local buckling
Plastic capacity
Compact section
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Clause/(Eqn)
Commentary
Code Message
Non compact section
Slender section
4.2.4.8. AISC LRFD - Bending Strength Box and RHS
Clause/(Eqn)
Commentary
Code Message
Lateral Torsional Buckling
Limited Buckling Moment
Compact section
Non compact section
176
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Slender section
Flange Local Buckling
Compact section
Non compact section
Slender section
Web Local Buckling
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Code Message
Compact section
Non compact section
Slender section
4.2.4.9. AISC LRFD - Bending Strength Tubes
Clause/(Eqn)
Commentary
Code Message
Flange Local Buckling
178
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Compact section
Non compact section
Slender section
4.2.4.10. AISC LRFD MEMB - Shear
Clause/(Eqn)
Commentary
Code Message
Shear z
Shear y
Web plate buckling coefficient is taken assuming
that no stiffeners are required i.e. k = 5
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Clause/(Eqn)
Commentary
Code Message
The shear term is computed for each axis using
the appropriate terms for the axis under consideration.
180
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
4.2.4.11. AISC LRFD MEMB - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
Shear
Pure Bending
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4.2.4.12. AISC LRFD MEMB - Combined Stress Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial compression and bending check
This check is strictly only valid if the member is
part of a non sway frame, i.e. k < 1.0, since
second order moments are ignored. If part of a
sway frame, a hand check is recommended.
Axial tension and bending check
182
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
4.2.4.13. AISC LRFD MEMB - Bending Coefficient, Cb
Clause/(Eqn)
Commentary
Message
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Message
4.2.4.14. AISC LRFD MEMB - Amplification Reduction Factors, Cmy, Cmz
Clause/(Eqn)
184
Commentary
Message
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Message
4.2.5. AISC LRFD MEMBER CHECKS - 3rd Edition
The equations defined in the following section assume units of Kips and inches.
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4.2.5.1. AISC LRFD - 3rd Edition - Partial Coefficients
Clause/(Eqn)
Commentary
Code Message
Resistance factors
Load coefficients
BEAMST assumes the appropriate factors have
already been applied by the user.
4.2.5.2. AISC LRFD - 3rd Edition - Nominal Axial Tension Strength
Clause/(Eqn)
Commentary
Code Message
Yielding on gross section
Limiting slenderness ratio
4.2.5.3. AISC LRFD - 3rd Edition - Nominal Axial Compressive Strength
Clause/(Eqn)
Commentary
Code Message
Limiting slenderness ratio
186
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Web
Rolled section flange
Fabricated section flange
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Clause/(Eqn)
Commentary
Code Message
Web
If rolled hollow section or constant thickness
box
If fabricated box with different thickness
plates
188
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Flange
Column slenderness parameter
Critical stress
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Clause/(Eqn)
Commentary
Code Message
Nominal strength
4.2.5.4. AISC LRFD - 3rd Edition - Bending Strength
Clause/(Eqn)
Commentary
Code Message
Compressive flange residual stress
4.2.5.5. AISC LRFD - 3rd Edition - Major Axis Bending Strength
Clause/(Eqn)
Commentary
Code Message
Plastic capacity
The nominal flexural strength, Mn, is the lowest
value obtained according to the limit states of:
Yielding, Lateral Torsional Buckling, Flange Local
Buckling, Web Local Buckling
Lateral Torsional Buckling
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Non compact limit
Compact section
Non compact section
Slender section
Flange local buckling
Compact section
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Clause/(Eqn)
Commentary
Code Message
Non compact section
Slender section
Web local buckling
Compact section
Non compact section
Slender section
192
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
4.2.5.6. AISC LRFD - 3rd Edition - Slender web
Clause/(Eqn)
Commentary
Code Message
Tension flange yield
Flange local buckling
Fcr is computed as follows for the limit states of
lateral torsional buckling and flange local buckling and the lower value used.
Lateral torsional buckling
Flange local buckling
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Clause/(Eqn)
Commentary
Code Message
Critical stress Fcr
4.2.5.7. AISC LRFD - 3rd Edition - Minor Axis Bending Strength
Clause/(Eqn)
Commentary
Code Message
Flange local buckling
Plastic capacity
Compact section
194
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Non compact section
Slender section
4.2.5.8. AISC LRFD - 3rd Edition - Bending Strength Box and RHS
Clause/(Eqn)
Commentary
Code Message
Lateral Torsional Buckling
Limited Buckling Moment
Compact section
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Clause/(Eqn)
Commentary
Code Message
Non compact section
Slender section
Flange Local Buckling
Compact section
Non compact section
Slender section
Web Local Buckling
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
Compact section
Non compact section
Slender section
4.2.5.9. AISC LRFD - 3rd Edition - Bending Strength Tubes
Clause/(Eqn)
Commentary
Code Message
Flange Local Buckling
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Code Message
Compact section
Non compact section
Slender section
4.2.5.10. AISC LRFD MEMB - Shear
Clause/(Eqn)
Commentary
Code Message
Shear z
Shear y
Web plate buckling coefficient is taken assuming
that no stiffeners are required i.e. k = 5
198
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Code Message
The shear term is computed for each axis using
the appropriate terms for the axis under consideration.
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BEAMST AISC Theory
Clause/(Eqn)
Commentary
Code Message
4.2.5.11. AISC LRFD MEMB - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
Shear
Pure Bending
200
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
4.2.5.12. AISC LRFD MEMB - Combined Stress Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial compression and bending check
This check is strictly only valid if the member is
part of a non sway frame, i.e. k < 1.0, since
second order moments are ignored. If part of a
sway frame, a hand check is recommended.
Axial tension and bending check
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BEAMST AISC Theory
4.2.5.13. AISC LRFD MEMB - Bending Coefficient, Cb
Clause/(Eqn)
202
Commentary
Message
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AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB)
Clause/(Eqn)
Commentary
Message
4.2.5.14. AISC LRFD MEMB - Amplification Reduction Factors, Cmy, Cmz
Clause/(Eqn)
Commentary
Message
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BEAMST AISC Theory
Clause/(Eqn)
204
Commentary
Message
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Chapter 5: BEAMST API Theory
The API command data block is used to request member and joint checking to the API WSD standard
(Ref. 2) and API LRFD standard (Ref. 3) for tubular sections.
5.1. API Working Stress Design Allowable Member Stress Check (API WSD
ALLO)
This section discusses the following topics:
5.1.1. API WSD ALLO Overview
5.1.2. API WSD ALLO Unity Check Report
5.1.3. API WSD ALLO Nomenclature
5.1.4. API WSD ALLO Stresses and Unity Checks
5.1.5. Spectral Loadcases
5.1.1. API WSD ALLO Overview
The API WSD ALLO header command in BEAMST is used to request member stress checks to API
Working Stress Design recommendations (Ref. 2). The strength requirements of API WSD 21st ed (Ref.
26), as applicable to BEAMST, are the same as those of API WSD 20th ed (Ref. 2). Hence the equations
for API 20th ed given in BEAMST API Theory (p. 205) of this manual also apply to API 21st ed.
The API WSD ALLOwable Command exists as a derivative of the AISC allowable stress check data described in AISC Load and Resistance Factor Design Member Check (AISC LRFD MEMB) (p. 157). The stress
check follows an identical path to the AISC check except for TUBE elements or other beam types that
have been assigned circular tubular sections in the structural analysis. For such elements the code
checks are performed to the American Petroleum Institute supported design recommendation API RP2A,
which refers to the AISC specification (Ref. 1), but amplifies the clauses particular to tubular members.
Unstiffened tubular local buckling, allowable stresses taking into account inelastic shell buckling,
member buckling and yield strength and unity checks are all performed to the API recommendations
as detailed in API LRFD Allowable Stresses and Unity Checks (p. 271). Amplification-reduction factors,
Cmy and Cmz, are restricted to a maximum of 0.85 unless these values are user defined. TUBE element
effective shear areas are rigidly restricted to one half of the cross-section area.
The API specification is written in terms of member yield strengths, so a YIELd command must be used
to specify the yield strength. The units of the yield strength must be those of the UNIT command.
Members may be selected for processing by elements and/or groups. The member section types must
be specified (if not specified in the structural analysis) using DESI commands. Further commands are
available for defining topological characteristic of the members (EFFE, UNBR and ULCF) and specifying
members that are classified as ‘secondary’ (SECO).
Loadcases from the preceding structural analysis may be selected for processing using the CASE command
and/or new loadcases formed from combinations of existing loadcases using the CMBV and COMB
commands. The AISC/API permitted one third increase in allowable stresses for wind extreme loading
may be requested on a loadcase basis using the EXTR command. For seismic conditions, API permits a
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205
BEAMST API Theory
higher increase in basic allowable stresses for strength assessment taking member allowable actions
to the point of first yield. This may be requested on a loadcase basis using the QUAK command.
The SECT command may be used to define intermediate points along a member at which member
forces are to be evaluated, checked and reported. These are in addition to results automatically printed
at the member end points and positions of any step change in cross-section properties. For the code
checks it is necessary to ensure the maximum acting bending moment and stresses are evaluated. Since
this may not occur at one of the ‘selected’ locations, BEAMST has a SEARch command which causes the
moments and stresses to be evaluated at every L/4 and L/6 (L = beam length) for prismatic and stepped
beams respectively. These extra locations are in addition to those selected and the results at these
locations are only presented if they give the maximum moments or stresses.
The selection of output reports is made using the PRIN command with the appropriate parameters for
the required reports. The PRIN command is also used to request the various summary reports available
and to set exceedence values for the unity checks. Four summary reports are available:
Summary report 1 is requested with the PRIN SUM1 command and gives the highest local buckling,
global buckling and yield unity check values for each element.
Summary report 2 is requested with the PRIN SUM2 command and gives the highest buckle check and
all unity checks at the section with the highest yield combined stress unity check for each element.
Summary report 3 is requested with the PRIN SUM3 command and consists of the highest unity check
for each selected loadcase for each element selected.
Summary report 4 is requested with the PRIN SUM4 command and provides the three worst unity checks
for each selected group, together with the distribution of unity check values. The distribution provides
information on the number of unity checks exceeding an upper limit (default 1.0), less than a lower
limit (default 0.5), and the number in the mid-range.
A complete list of the command set available for the API WSD code checks is given in Table 5.1: API
WSD ALLO Commands (p. 206) below and described in detail in BEAMST Command Reference (p. 51).
An example data file is given in Example 5.1: Example of an API WSD ALLO data file (p. 207).
Table 5.1: API WSD ALLO Commands
Command
Description
Usage
API WSD
ALLO
API allowable stress header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SEAR
Search for maximum forces and stresses
SECO
Secondary members
DESI
Defines design section properties
C
3
PROF
Section profiles for use in design
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
Command
Description
Usage
Note
EFFE
Effective lengths/factors
CB
Pure bending Cb coefficient
CMY/CMZ
Amplification reduction factors Cmy/Cmz
UNBR
Unbraced lengths of element
ULCF
Unbraced length of compression flange
CASE
Basic loadcases to be reported
C
4
COMB
Define a combined loadcase for processing
C
4
CMBV
Define a combined loadcase for processing
C
4
SELE
Select/redefine a combined/basic loadcase
title
SPEC
RENU
Basic loadcases from response spectrum
analysis
EXTR
Renumber a ‘basic loadcase’
QUAK
Loadcases allowing 33% overstress
Loadcases with earthquake permitted overstress
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. Compulsory for non-tubular elements unless Sections have been used in the preceding analyses for all
elements to be processed.
4. At least one CASE, CMBV or COMB command must be included.
Example 5.1: Example of an API WSD ALLO data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
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BEAMST API Theory
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
API ED20 ALLO
*
* Horizontal plan bracing level -50 m
*
GROU 1
UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Indicate that these loadcases are extreme events
*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main plan bracing members use effective length
* coefficient of 0.8
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFE 0.8 ELEM 105 106
EFFE 0.8 ELEM 101 TO 104
EFFE 0.8 ELEM 107 TO 110
EFFE 1.0 GROU 1
*
* Out of plane unbraced lengths need redefining
*
UNBR FACT 2.0 1.0 ELEM 105 106
UNBR LENG 15.0 7.5 ELEM 102 103
*
* Override program computed moment amplification RF
*
CMY 0.85 ELEM 102 103 105 106
CMZ 0.85 ELEM 102 103 105 106
*
* Check mid-span sections
*
SECT 0.5 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 SUM2 SUM3 SUM4 BOTH
END
STOP
5.1.2. API WSD ALLO Unity Check Report
The unity check report is presented on an element by element basis. The header line displays the element
number, the associated node numbers, the element group number and the units in use. The results are
printed for each of the selected positions (or sections) on the element for each loadcase in turn. The
first columns of the report define the loadcase, section number and position as a ratio of the elements
length.
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
The allowable stresses for axial, shear and bending (in local Y and Z axes) stresses are presented in the
next columns of the report. These are preceded by an alpha numeric descriptor (CODE) that indicates
the derivation of each of the allowable stresses. These descriptors are of the form:
T.XVYZ or C.XVYZ
T or C defines whether the member is in tension or compression, XVYZ are individual alpha codes which
relate to the axial(X), shear(V), and bending(Y,Z) allowable stresses. These alpha codes specify the design
code clause or equation used to evaluate the allowable stresses and are defined in Table 5.2: Allowable
Stress Alphabetic Codes (p. 209):
Table 5.2: Allowable Stress Alphabetic Codes
Stress
V
Code
Clause
Description
A
AISC B7
axial tension - B7 satisfied
B
AISC B7
axial tension - B7 violated
C
(3.2.2-1)
axial compression - kL/r < Cc
E
(3.2.2-2)
axial compression - kL/r >= Cc
B
AISC (F4-2)
shear buckle
Y
AISC (F4-1)
shear yield
U
user defined allowable
Y
C
(3.2.2-1a)
bending D/t <= 1500/fy
Z
G
(3.2.2-1b)
bending 1500/fy < D/t < 3000/fy
H
(3.2.2-1c)
bending 3000/fy < D/t < 300
For example, the unity check CODE combination
C.CYCC
indicates that the member is in compression and that the following clause/equations were used to derive
the allowable stresses:
• Axial - C = (3.2.2-1) axial compression - kL/r < Cc
• Shear - Y = AISC (F4-1) shear yield
• Bending - C = (3.2.2-1a) bending - D/t <= 1500/fy
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BEAMST API Theory
The last two characters are always the same for tubular members.
The final column of the table, headed Messages, flags all lines of results where any of the checks have
failed. These messages may be summarized as follows:
FAIL
Code check failure for this member
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
THKF
Wall thickness less than ¼ inch
DTRF
D/t ratio exceeds 300
YIEL
Yield stress greater than 60 ksi
SLRF
Slenderness ratio greater than 200 for a compression member
SLRW
Slenderness ratio greater than 300 for a tension member
SHYF
Shear yielding failure
5.1.3. API WSD ALLO Nomenclature
The API WSD ALLO uses following nomenclature:
5.1.3.1. API WSD ALLO Nomenclature - Dimensional
5.1.3.2. API WSD ALLO Nomenclature - Acting Section Forces and Stresses
5.1.3.3. API WSD ALLO Nomenclature - Allowable Stresses and Unity Checks
5.1.3.4. API WSD ALLO Nomenclature - Parameters
5.1.3.1. API WSD ALLO Nomenclature - Dimensional
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
D
Tube outside diameter
t
Thickness
k
Effective length factor
L
Unbraced length of member
r
Radius of gyration
5.1.3.2. API WSD ALLO Nomenclature - Acting Section Forces and Stresses
N
Axial force
Nely,z
Euler force in y or z direction
My,z
Bending moment about y or z
fa
Axial stress
fby, fbz
Bending stresses about y and z
fv
Maximum shear stress
fvm
von Mises stress
Mo
Maximum free bending moment from all sections examined along member
5.1.3.3. API WSD ALLO Nomenclature - Allowable Stresses and Unity Checks
fy
Yield stress
Fxe
Elastic local buckling stress
Fxc
Inelastic local buckling stress
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Fa
Allowable axial compressive stress
Ft
Allowable axial tensile stress
Fb
Allowable bending stress
Fv
Allowable flexural shear stress
Fvt
Allowable torsional shear stress
Fe
Euler stress divided by a factor of safety
UCax
Axial unity check
UCvmax
Flexural shear unity check
UCTOR
Torsional shear unity check
UCby
Pure bending check about y axis
UCbz
Pure bending check about z axis
UCCB
Combined axial compression and bending buckle check
UCY
Combined axial and bending yield unity check member
UCCSR
Upper bound member buckling unity check
5.1.3.4. API WSD ALLO Nomenclature - Parameters
E
Young's modulus
Cmy, Cmz
Moment amplification reduction factors
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
5.1.4. API WSD ALLO Stresses and Unity Checks
This section discusses the following topics:
5.1.4.1. API WSD ALLO Stress Increase
5.1.4.2. API WSD ALLO - Tension
5.1.4.3. API WSD ALLO - Compression
5.1.4.4. API WSD ALLO - Bending
5.1.4.5. API WSD ALLO - Shear
5.1.4.6. API WSD ALLO - Unity Checks
5.1.4.7. API WSD ALLO - Combined Stresses
5.1.4.1. API WSD ALLO Stress Increase
Working stress design codes permit allowable stresses to be increased above those appropriate to Ordinary conditions for other conditions. The percentage increase in allowable stresses to be applied to
the allowable stresses quoted herein for different loadcase types are:
Type
Axial/Bending
Shear
Ordinary
0.0
0.0
Extreme
33.33
33.33
Earthquake
70.0
44.34
The following section describes the computations undertaken for tubular sections only (with two exceptions, see below). For non-tubular members being checked to API reference should be made to Allowable
Stresses and Unity Checks for the AISC code. Note that the combined Unity Checks for non-tubular
members utilize modified parameters based upon API recommendations. See Notes 1 and 2 in API WSD
ALLO - Combined Stresses (p. 216).
5.1.4.2. API WSD ALLO - Tension
Clause/(Eqn)
Commentary
Code Message
Allowable stress
Limiting Slenderness Ratio
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5.1.4.3. API WSD ALLO - Compression
Clause/(Eqn)
Commentary
Code Message
5.1.4.4. API WSD ALLO - Bending
Clause/(Eqn)
214
Commentary
Code Message
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
5.1.4.5. API WSD ALLO - Shear
Clause/(Eqn)
Commentary
Code Message
Beam Shear
Torsional Shear
5.1.4.6. API WSD ALLO - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
Shear
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Clause/(Eqn)
Commentary
Code Message
Pure Bending
5.1.4.7. API WSD ALLO - Combined Stresses
Clause/(Eqn)
Commentary
Code Message
Axial compression and bending buckle check
Axial tension and bending buckle check
UCB1 is set = 0.0
Combined axial and bending yield check
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
Clause/(Eqn)
Commentary
Code Message
Buckle CSR check
UCCSR
This uses the same equation (3.3.1-4) as the axial
compression and bending buckle check but
utilizes the maximum stresses and the minimum
member properties occurring along the member
in order to compute an upper bound buckle
check. It should be noted that this check often
results in high utilization ratios which may not
occur in practice, but indicates a need to undertake a more rigorous hand analysis of the member.
5.1.5. Spectral Loadcases
In response spectrum analysis using modal superposition (Ref. 12) the structure displacements and
forces calculated represent estimated maxima and are, in general, unsigned (positive).
For the purpose of checking members to API a series of worst case static-spectral loadcase permutations
must be generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depend upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition.
5.1.5.1. Torsional Effects
The maximum torsional spectral load contribution at each beam section position is deduced in a similar
manner to the axial load contribution in 5.1.5.2.
5.1.5.2. Axial Unity Check and the Axial Component of Combined Stress Buckle and
Yield Unity Checks
The maximum axial spectral load contribution at each beam section position is calculated by assuming
that the spectral axial load distribution is linear with both member end loads having the same sign.
The sign adopted for these member spectral end loads is normally assumed to be of the same sign as
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the static axial load (if it exists). In cases where the static loadcase is tensile it is possible that reversing
the sign of the spectral case may produce a net compressive load and, hence, a more onerous utilization
(since buckling may become a problem). Under these conditions, the checks are repeated with the
spectral axial stresses reversed with respect to the static case, and the combination producing the
highest utilization of both conditions is reported. The sign adopted may be ascertained from the utilization code reported.
As in all checks performed by BEAMST, zero axial stress is treated as compressive (-ve sign, ASAS convention).
5.1.5.3. Local Axes Shear Unity Checks and Maximum Shear Unity Check for Tubular
Sections
In order to be able to generate mid-member stresses an equivalent member spectral loading is required.
BEAMST assumes that the spectral loading consists of a linearly varying inertia loading on the member
acting in a rigid fashion (that is, the load consists of that due to pure translation and rotation of the
member). This inertia loading is calculated by ‘balancing’ it against the member signed spectral end
forces (shears and moments).
For each local bending plane there are sixteen unique signed spectral end force (shears and moments)
expansions/cases of which eight are symmetric, but of opposite sign, to the remaining eight. Each of
these sixteen signed spectral expansions is denoted by a single alphabetic letter code in BEAMST in
the range A-P as shown in Table 5.3: Automatic Signed Spectral Expansion Codes for Member Checks
and the Respective Signs Applied for Bending in the Local Y-Y/Z-Z Planes (p. 220). For spectral loadcases
only eight of the sixteen possible expansions need theoretically be considered but for static-spectral
summations all sixteen have to be taken into account.
The Shear Unity Checks are maximized by adopting the static-spectral signed expansion which maximizes
the total acting shear at each beam section position. For tubular sections the combination of staticspectral expansions which maximizes the resultant acting shear on the cross section and the Maximum
Shear Unity Check.
For a linearly varying inertia load it can be deduced a priori that the following spectral expansions are
critical for the Shear Unity Checks for static-spectral summation.
Beam section position (α)
Local axes spectral expansion
0 < α < 1/3
E or L
1/3 < α < 2/3
D or M
2/3 < α < 1
B or O
5.1.5.4. Local Axes Pure Bending Unity Checks and Bending Components of Combined
Stresses Yield Unity Check
For bending unity checks and unity check bending components it is necessary to determine the spectral
expansion which maximizes the ratio of acting to allowable stress as opposed to simply maximizing
the acting bending stress. In general this is necessary because the bending allowable may be a function
of Cb which itself is a function of the signs and relative magnitudes of the member total end forces.
BEAMST investigates each of the sixteen signed spectral expansions shown in Table 5.3: Automatic
Signed Spectral Expansion Codes for Member Checks and the Respective Signs Applied for Bending in
the Local Y-Y/Z-Z Planes (p. 220) for both of the local axes bending planes for each beam section position
being considered and reports the critical expansions at each section. For tubular sections being checked
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API Working Stress Design Allowable Member Stress Check (API WSD ALLO)
to AISC where it is necessary to calculate bending resultants at each beam section the spectral expansions
which maximize the ratio of local axes bending stress to allowable are determined (as these local axes
acting bending stresses are the ones which also maximize the acting bending resultants and hence
maximize the yield unity check components).
For static-spectral summation it is theoretically necessary to investigate all sixteen spectral expansions
for the worst cases but for loadcases composed of expanded spectral contributions only, the following
generalizations can be made:
1. The acting bending stress at each beam section position is maximized by adopting the spectral expansion
defined by end moments of the same sign and end shears of opposite signs.
2. Where the allowable stress is a function of Cb, the allowable will be minimized by adopting the expansion
with spectral end moments of the same sign as this minimizes Cb.
These two generalizations taken together infer spectral expansions A or P (Table 5.3: Automatic Signed
Spectral Expansion Codes for Member Checks and the Respective Signs Applied for Bending in the
Local Y-Y/Z-Z Planes (p. 220))
5.1.5.5. Unity Check Report for Shear, Pure Bending and Yield Unity Checks
The Unity Check Report for a spectral or a static-spectral summation comprises four separate reports:
1. Highest Shear Unity Checks
2. Highest Pure Bending Unity Checks
3. Highest Yield Unity Checks
4. Highest Buckle Unity Checks
The unity checks of direct interest to the user when checking against a design code are the shear checks
in the Highest Shear Unity Checks, the pure bend checks in the Highest Pure Bending Unity Checks etc.
For the Highest Shear, Pure Bending and Yield Reports, the worst unity check at each beam section
position is reported together with the spectral expansions in the local Y and Z which maximize the respective checks (as described in Torsional Effects, Axial Unity Check and the Axial Component of Combined Stress Buckle and Yield Unity Checks, Local Axes Shear Unity Checks and Maximum Shear Unity
Check for Tubular Sections and Local Axes Pure Bending Unity Checks and Bending Components of
Combined Stresses Yield Unity Check above) appended to the loadcase number. In addition to the unity
checks of direct interest in each report all remaining unity checks are calculated for the spectral expansions quoted and are reported. This allows users to obtain an overall picture of stress state in the beam
at the section under consideration for the spectral expansions cited. The combined buckle unity checks
in these reports and the Highest Buckle Unity Check Report are explained in API Combined Stress Buckle
Unity Check below.
5.1.5.6. API Combined Stress Buckle Unity Check
As for the pure bending and yield unity check it is necessary to determine which spectral expansions
maximize the bending components of the buckle unity check defined by ratio of ‘equivalent uniform
bending’ stress to minimum allowable. This is necessary because the amplification-reduction factor Cm
used to convert maximum acting bending stress to an equivalent uniform bending stress is a function
of the signs and relative magnitudes of the member total end forces (moments).
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BEAMST API Theory
BEAMST investigates all sixteen spectral expansions determining for each expansion the maximum
bending stress and minimum allowable stress occurring anywhere along the beam and the buckle unity
check bending component for the bending plane being considered. Over all sixteen expansions, those
which maximize the bending components in each of the local bending planes are used in the final
buckle check and are reported in the Highest Buckle Unity Check Report.
Table 5.3: Automatic Signed Spectral Expansion Codes for Member Checks and the Respective
Signs Applied for Bending in the Local Y-Y/Z-Z Planes
Spectral Expansion
End1
Shear
End1
Moment
End2
Shear
End2
Moment
A
+
+
-
+
B
+
+
-
-
C
+
+
+
+
D
+
+
+
-
E
+
-
-
+
F
+
-
-
-
G
+
-
+
+
H
+
-
+
-
I
-
+
-
+
J
-
+
-
-
K
-
+
+
+
L
-
+
+
-
M
-
-
-
+
N
-
-
-
-
O
-
-
+
+
P
-
-
+
-
Notes
1. Beam end spectral torque signs are chosen to be identical with their respective static components in
static-spectral loadcases.
2. Beam end spectral torque signs adopted for evaluation of spectral stresses at intermediate beam section
positions are chosen to be identical with their respective static stress components at the section under
consideration.
5.2. API Hydrostatic Collapse Check (API WSD HYDR)
This section discusses the following topics:
5.2.1. API WSD HYDR Overview
5.2.2. API Hydrostatic Unity Check Report
5.2.3. API WSD HYDR Nomenclature
5.2.4. API Allowable Stresses and Unity Checks
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API Hydrostatic Collapse Check (API WSD HYDR)
5.2.1. API WSD HYDR Overview
The API WSD HYDR header command is used to request that hydrostatic pressure, allowable stresses,
member actions, unity checks and combined stress hydrostatic collapse unity checks be performed to
API recommendations for TUBE elements, or other beam types that have been assigned tubular sections
in the structural analysis (Ref. 2).
Elements may be selected by ELEMent, GROUp and CASE/COMBine commands as in the POST and AISC
Command data blocks. Hydrostatic pressures, allowable stresses and collapse unity checks may be requested at any user selected position along the element using the SECTion command in BEAMST.
The calculation of hydrostatic pressures requires a knowledge of each member position with respect
to still water level, tide height, wave height and length as well as details of the sea medium and various
commands in BEAMST exist to define these. First a reference frame has to be specified for the (sea)
water axes and its origin position in terms of the jacket reference frame defined (i.e. the global co-ordinate system used in the previous ASAS analysis) using a MOVE command. (See BEAMST Command
Reference (p. 51) and Ref. 14). This command is optional and if omitted the water and jacket frame
origins are taken to coincide. Having defined the water axes origin, the relative orientations of water
and jacket axes must follow. For example the jacket axes may be inclined to the water axes if the jacket
is being considered in a semi-submerged position. In order to convert pressure heads to hydrostatic
pressure the coefficient of gravity in the vertical downwards (-Zwater) water direction is required. If the
components of this coefficient of gravity are specified in terms of the jacket axes then the water-jacket
axes orientation and the coefficient of gravity can be specified in a single operation. The GRAVity
command in BEAMST is available for this purpose and is compulsory for the API hydrostatic collapse
check. The jacket and water axes are now spatially fixed and the only remaining information required
for calculation of water static head is that of mean water level, sea bed level, density of seawater and
tide height. This information is specified using the compulsory ELEVation command. For completion a
further command WAVE is available for specification of wave height and period, for the inclusion of
wave induced pressure components. This command is optional and if omitted the static water head
only is considered. For calculation of hydrostatic head to API recommend
All elements selected for hydrostatic collapse post-processing are assumed to be unflooded and unstiffened (i.e. axial length of cylinder between stiffening rings, diaphragms or end connections is equal
to the element length). This unstiffened length may be defined explicitly using a ULCF command. This
command allows ring stiffened tubulars to be checked for hydrostatic pressure collapse between the
stiffening rings.
The API design code provides safety factors for axial tensile, compressive and compressive hoop loading
to be used in calculating allowable stresses for different design conditions. The code permits the user
some flexibility in the choice of the safety factor for axial compressive loading, indeed the factors given
for earthquake loading are only suggested ones. BEAMST allows EXTReme and QUAK commands to be
used for automatic selection of default safety factors for design extreme environmental and earthquake
(seismic) loading conditions respectively. These default values are given in API Allowable Stresses and
Unity Checks (p. 226). If required the user can override these default values in BEAMST using the SAFE
command.
A detailed Unity Check Report incorporating beam section hydrostatic depth, member acting and allowable stresses, membrane hoop and tension/compression - collapse interaction unity checks is available
and may be requested using the PRIN UNCK command.
The BEAMST commands applicable to the API hydrostatic collapse Command data are given in
Table 5.4: API WSD HYDR Commands (p. 222) below and are described in detail in BEAMST Command
Reference (p. 51). An example data file is given in Example 5.2: Example API WSD HYDR data file (p. 223).
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A summary report is also available.
Summary report number 1 is requested using the SUM1 subcommand and gives the highest unity check
values for each element.
Table 5.4: API WSD HYDR Commands
Command
Description
Usage
API
WSD
HYDR
API hydrostatic collapse header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
ELEV
Water depth and gravity
MOVE
Water axis origin in global structure axis system
WAVE
Wave height and period
GRAV
Gravitational acceleration relative to structure axis system
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
DESI
Defines design section properties
PROF
Section profiles for use in design
ULCF
Length of tubular members between stiffening rings, diaphragms, etc
CASE
Basic loadcases to be reported
C
3
COMB
Define a combined loadcase for processing
C
3
CMBV
Define a combined loadcase for processing
C
3
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a basic loadcase
EXTR
Loadcases allowing extreme loading overstress
QUAK
Loadcases with earthquake permitted overstress
SAFE
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
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C
C
API Hydrostatic Collapse Check (API WSD HYDR)
Command
Description
Usage
END
Terminates command data block
C
Note
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. At least one CASE, CMBV or COMB command must be included.
Example 5.2: Example API WSD HYDR data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
API ED20 HYDR
*
* Horizontal plan bracing level -50 m
*
GROU 1
UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Hydrostatic information
*
ELEVATION 0.0 -50.0 1.025
GRAVITY 0.0 0.0 -9.81
*
* Indicate that these loadcases are extreme events
*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Out of plane unbraced lengths need redefining
*
UNBR FACT 2.0 1.0 ELEM 105 106
UNBR LENG 15.0 7.5 ELEM 102 103
*
* Check mid-span sections
*
SECT 0.5 ELEM ALL
*
* Ask explicitly for all reports
*
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PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 BOTH
END
STOP
5.2.2. API Hydrostatic Unity Check Report
The final column of each report is reserved for messages. These may be summarized as follows:
FAIL
Code check failure for this member
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
FXHA
Net axial stress fax less than half allowable elastic hoop stress and thus eqn 3.3.4-3 not checked
DTRF
Allowed diameter thickness ratio exceeded (D/t >= 300)
THXF
Wall thickness less than recommended minimum of 6mm
YIEL
Yield strength greater than 414MPa (60ksi)
MOTN
Geometry parameter, used in the elastic hoop buckling stress, µ, greater than 1.6 D/t
UDTR
Unconservative (D/t > 120)
5.2.3. API WSD HYDR Nomenclature
API WSD HYDR uses the following nomenclature:
5.2.3.1. API WSD HYDR Nomenclature - Dimensional
5.2.3.2. API WSD HYDR Nomenclature - Acting Section Forces and Stresses
5.2.3.3. API WSD HYDR Nomenclature - Allowable Stresses and Unity Checks
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API Hydrostatic Collapse Check (API WSD HYDR)
5.2.3.1. API WSD HYDR Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
L
Unbraced length of member
5.2.3.2. API WSD HYDR Nomenclature - Acting Section Forces and Stresses
fh
Hoop stress
fat
Axial tensile stress
fac
Axial compressive stress
fb
Resultant bending stress
5.2.3.3. API WSD HYDR Nomenclature - Allowable Stresses and Unity Checks
Fhe
Elastic hoop buckling stress
Fhc
Critical hoop buckling stress
fy
Yield stress
E
Young's modulus
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γ
Poisson's ratio
Fb
Allowable bending stress
Fch
Allowable critical hoop buckling stress
Fxe
Critical axial elastic local buckling stress
Faa
Allowable axial elastic local buckling stress
Fxc
Inelastic axial local buckling stress
UCH
Hoop compressive unity check
UCT
Axial tension unity check
UCTH
Combined tension hydrostatic pressure unity check
UCCH1/2
Combined compression hydrostatic pressure unity check
5.2.4. API Allowable Stresses and Unity Checks
Safety factors for use with local buckling and interaction formulae herein are:
Type
Axial compression SFxc
Axial tension
SFxt
HOOP Compres- Bending SFb
sion SFhc
Ordinary
1.67-2.00
1.67
2.00
Extreme
1.25-1.50
1.25
1.50
Earthquake
1.00-1.20
1.00
1.20
See Combined
Compression
and Hydrostatic
Pressure Unity
Check
The default values are shown in bold.
The value of SFxc is overwritten by the AISC axial compression safety factor if exceeded by the AISC
value.
The AISC value is:
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API Hydrostatic Collapse Check (API WSD HYDR)
(AISC E2-1)
where (KL/r) is the slenderness ratio and
If the slenderness ratio exceeds Cc the AISC value is taken as 23/12 (AISC E2-2), where BEAMST default
values are underlined.
In the hydrostatic collapse check the following assumptions are made:
1. All members are unflooded.
2. Out-of-roundness is assumed to be within API RP2B tolerance limits.
3. Wave crest is assumed to be directly above the beam section position under consideration.
4. Hydrostatic pressure is only considered for beam section positions below the static water level (=mean
water level + tide height + storm surge height).
5. The wave length, Lw, is adequately described by linear wave theory as follows:
a. If
(shallow water)
then
b. Else if
and
(deep water)
then
c. Else Lw is obtained iteratively from
where:
• d = static water depth
• g = acceleration due to gravity
• Tw = wave period
6. The design head is given by
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BEAMST API Theory
where:
•
• Hw = wave height
• z = depth below static water surface
7. The design head induced hoop stress is given by
where:
• p = γgHz
• γ = water density
5.2.4.1. API Allowable - Limit Checks
Clause/(Eqn)
228
Commentary
Message
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API Hydrostatic Collapse Check (API WSD HYDR)
5.2.4.2. API Allowable - Elastic Hoop Buckling Stress Fhe
Clause/(Eqn)
Commentary
Message
5.2.4.3. API Allowable - Critical Hoop Buckling Stress Fhc
Clause/(Eqn)
Commentary
Message
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5.2.4.4. API WSD - Allowable Critical Hoop Buckling Stress Fch
Clause/(Eqn)
Commentary
Message
5.2.4.5. API WSD - Critical Axial Elastic Local Buckling Stress Fxe
Clause/(Eqn)
Commentary
Message
5.2.4.6. API WSD - Allowable Axial Elastic Local Buckling Stress Faa
Clause/(Eqn)
Commentary
Message
5.2.4.7. API WSD - Inelastic Axial Elastic Local Buckling Stress Fxc
Clause/(Eqn)
Commentary
Message
5.2.4.8. API WSD - Hoop Compressive Unity Check UCH
Clause/(Eqn)
230
Commentary
Message
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API Joint Strength Check (API WSD JOIN)
5.2.4.9. API WSD - Axial Tension Unity Check UCT
Clause/(Eqn)
Commentary
Message
5.2.4.10. API WSD - Combined Compression and Hydrostatic Pressure Unity Check
UCCH1/2
Clause/(Eqn)
Commentary
Message
5.2.4.11. API WSD - Combined Tension and Hydrostatic Pressure Unity Check UCTH
Clause/(Eqn)
Commentary
Message
5.3. API Joint Strength Check (API WSD JOIN)
This section discusses the following topics:
5.3.1. API WSD JOIN Overview
5.3.2. API WSD JOIN Check Report
5.3.3. API WSD JOIN Nomenclature
5.3.4. API WSD JOIN Allowable Loads and Unity Checks
5.3.5. Spectral Expansion for Joint Checks (API WSD JOIN)
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BEAMST API Theory
5.3.1. API WSD JOIN Overview
The API WSD JOIN command requests that a joint check be performed. The check differs from the
punching shear check as defined in revision 2 of the 21st edition of the API’s RP 2A-WSD Clause 4.3 or
later editions, this supersedes earlier NOMI or PUNC checks required for earlier versions.
The joints may consist of TUBE elements and/or other beam types that have been assigned tubular
sections in the structural analysis.
Joints for the API check post-processing are selected using the JOINt command in BEAMST which specifies
the node numbers at joint positions. All joints are assumed ‘simple’. Elements may be excluded from
the joint punching shear check using the SECOndary command.
Joints are automatically classed as a combination of K, T or Y depending on the loading applied. A
maximum of 5 types per brace member is permitted; results are produced for each brace forming the
joint.
1. The chord member is the member with the greatest outside diameter.
2. If two or more potential chord members have equal diameters; BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
3. In the case of two or more potential chord members with equal diameters and wall thicknesses, the first
two encountered as shown in the Cross Check Report will be considered.
4. If the CHOR command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
A joint is formed of a maximum of 3 nodes connected by valid chord members. These nodes must form
a straight line and must be within a distance of D/4. This process is performed automatically, however,
if required can be specified manually using the CHOR command.
All valid members that form the joint are allocated to a number of planes. A tolerance of +/- 15° exists
to identify braces belonging to the same plane. Each member in each plane is then assessed to obtain
unity factors for axial and bending forces in addition to an interaction ratio to account for the combination of such forces.
BEAMST automatically decides on the type of joint by assessing the balancing axial force in each valid
brace member forming the joint. Firstly any load paths that form a K joint are assessed; it can be the
case that in a traditional KT Joint shape that this will result in 2 K joints with different gaps between
members.
All forces that transfer across the joint to an opposite brace will form X Joints; again it is possible that
multiple X Joint load paths co-exist within one joint; in this case these will be calculated with the appropriate offsets. Finally, any shear that exists in a joint will be accounted for by the provision of a Y
joint type. The final joint capacity will be calculated using the proportion of axial load that is allocated
to each of the joint types.
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API Joint Strength Check (API WSD JOIN)
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHOR commands. Interpolated joint
classifications may be defined using the TYPE command. For K joints a gap dimension appropriate to
the joint may be specified in the TYPE command. A default gap dimension may be specified using the
GAPD command.
The detailed joint check report provides information on joint geometric parameters, type, acting chord
and brace stresses, punching shear, Qf and Qu factors, punching shear allowable(s), and unity checks.
This may be requested using the PRINt UNCK command. The maximum unity check is flagged for ease
of reference. When an interpolatory joint type classification is being employed two sets of punching
shear allowables are reported, one for each joint classification type and these pertain to joints classified
as 100% of the respective joint types.
Summary report 3 comprises the highest unity check for each selected loadcase for each joint.
Summary report 4 comprises the three worst unity checks for each selected joint, together with the
distribution of unity check values. This distribution provides information on the number of unity checks
exceeding an upper limit (default 1.0), less than a lower limit (default 0.5), and the number in the mid
range.
BEAMST commands applicable to the API punching stress command are given in Table 5.5: API WSD
JOIN Commands (p. 233) below and are described in detail in BEAMST Command Reference (p. 51). An
example data file is given in Example 5.3: Example API WSD JOIN data file (p. 234).
Table 5.5: API WSD JOIN Commands
Command
Description
Usage
Note
API WSD JOIN
API joint check header command
C
UNIT
Units of length and force
YIEL
Yield stress
JOIN
Joint numbers to be reported
TYPE
Joint type and brace element definition
CHOR
Chord elements at a joint
SECO
Secondary members to be ignored in checks
DESI
Defines design section properties
GAPD
Defines default gap dimension
PROF
Section profiles for use in design
STUB
Tubular member end stub dimensions
CASE
Basic loadcases to be reported
C
2
COMB
Define a combined loadcase for processing
C
2
CMBV
Define a combined loadcase for processing
C
2
1
C
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Command
Description
SELE
Select/redefine a combined/basic loadcase
title
Usage
Note
SPEC
RENU
Basic loadcases from response spectrum
analysis
EXTR
Renumber a basic loadcase
QUAK
Loadcases allowing extreme loading overstress
Loadcases with earthquake permitted overstress
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 5.3: Example API WSD JOIN data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
API ED21 JOIN
*
* Investigate all joints in the model except where
* only one element is connected
*
JOINT ALL
NOT JOINTS 1315 1355 5110 5150
*
* Ignore dummy elements
*
SECONDARY ELEMENTS 801 802
UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
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API Joint Strength Check (API WSD JOIN)
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Indicate that these loadcases are extreme events
*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Specify the chord elements for one of the joints
*
CHORD 1130 122 123
*
* Set some joints as being Y
*
TYPE.OF.JOINT 1130 Y 102
TYPE.OF.JOINT 1130 Y 103
*
* Ask explicitly for all reports
*
PRIN XCHK UNCK SUNI N MM SUM3 BOTH SUM4 BOTH
END
STOP
5.3.2. API WSD JOIN Check Report
The detailed JOINT check report provides information on joint geometric parameters, type, acting chord
and brace loading, Qf, and Qu factors, nominal load allowables and unity checks. This may be requested
using the PRINt UNCK command. The maximum unity check is flagged for ease of reference.
Messages displayed in output reports or obtained from the database have the following meanings:
FAIL
Unity check value exceeds unity
PNT9
Unity check value exceeds 0.9
NOCK
No check has been carried out, due to one of the following error messages
BETA
Beta value β is outside the valid API range1 (Checks can continue with OPTI JRNG)
THET
Theta value θ is outside the valid API range1 (Checks can continue with OPTI JRNG)
GAMA
Gamma value γ is outside the valid API range1 (Checks can continue with OPTI JRNG)
NOCY
Computed Py value is less than zero
DIST
The distance between work points exceeds D/42
1
Error message
2
Warning message
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5.3.3. API WSD JOIN Nomenclature
API WSD JOIN uses the following nomenclature:
5.3.3.1. API WSD JOIN Nomenclature - Dimensional
5.3.3.2. API WSD JOIN Nomenclature - Acting Forces and Stresses
5.3.3.3. API WSD JOIN Nomenclature - Allowable Stresses and Unity Checks
5.3.3.1. API WSD JOIN Nomenclature - Dimensional
D
Chord outside diameter
d
Brace outside diameter
R
Chord radius
T
Chord thickness
t
Brace thickness
γ
Ratio between the chord radius and thickness
τ
Ratio between the thickness of the brace and chord
θ
Angle between brace and chord
β
Ratio between the diameter of the brace and chord
g
K joint gap
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API Joint Strength Check (API WSD JOIN)
5.3.3.2. API WSD JOIN Nomenclature - Acting Forces and Stresses
P
Brace axial force
Mip
Brace in-plane bending moment
Mop
Brace out-of-plane bending moment
faxc
Chord axial stress component
fipc
Chord in-plane bending stress
fopc
Chord out-of-plane bending stress
fa
Brace axial stress component
fip
Brace in-plane bending stress
fop
Brace out-of-plane bending stress
fb
Resultant brace bending stress
5.3.3.3. API WSD JOIN Nomenclature - Allowable Stresses and Unity Checks
fyc
Chord yield stress
Pa
Allowable axial force
Maip
Allowable in-plane bending moment
Maop
Allowable out-of-plane bending moment
UCax
Axial force unity check
UCip
In-plane bending unity check
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UCop
Out-of-plane bending unity check
UCBN
Combined bending unity check
5.3.4. API WSD JOIN Allowable Loads and Unity Checks
This section discusses the following topics:
5.3.4.1. API WSD JOIN Allowable - Basic Capacity
5.3.4.2. API WSD JOIN Allowable - Strength Factor Qu
5.3.4.3. API WSD JOIN Allowable - Strength Factor Qf
5.3.4.4. API WSD JOIN - Joints with Thickened Cans
5.3.4.5. API WSD JOIN - Nominal Load Unit Checks
5.3.4.6. API WSD JOIN - Combined Axial and Bending Unity Checks
5.3.4.1. API WSD JOIN Allowable - Basic Capacity
Clause/(Eqn)
Commentary
Message
µ = 1.0 for ordinary loadcases
= 1.33 for extreme loadcases
= 1.6 for earthquake loadcases
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API Joint Strength Check (API WSD JOIN)
5.3.4.2. API WSD JOIN Allowable - Strength Factor Qu
Clause/(Eqn)
Commentary
Message
5.3.4.3. API WSD JOIN Allowable - Strength Factor Qf
Clause/(Eqn)
Commentary
Message
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5.3.4.4. API WSD JOIN - Joints with Thickened Cans
Clause/(Eqn)
Commentary
Message
5.3.4.5. API WSD JOIN - Nominal Load Unit Checks
Clause/(Eqn)
Commentary
Message
5.3.4.6. API WSD JOIN - Combined Axial and Bending Unity Checks
Clause/(Eqn)
Commentary
Message
5.3.5. Spectral Expansion for Joint Checks (API WSD JOIN)
In response spectrum analysis using modal superposition (Ref. 12) structure displacements and forces
calculated represent estimated maxima. Such estimated maxima are, in general, unsigned (positive).
For the purpose of checking joints to API, a series of worst static-spectral possible loadcases must be
generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depends upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
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API Punching Shear Joint Check (API WSD PUNC)
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition. Any joint type identification dependant on
axial load is carried out prior to any combinations with dynamic cases.
There are eight possible unique combinations of signs, or ‘spectral expansions’, which can be applied
to unsigned spectral axial and local bending stresses:
2 - axial (tension and compression)
x
2 - local Y bending (hog and sag)
x
2 - local Z bending (hog and sag)
and each is denoted by a single alphabetic letter code in BEAMST in the range R-Y as shown in Figure 5.2: Automatic Signed Spectral Expansion Codes for Joint checks and the Respective Signs Applied
to Chord/Brace Unsigned Spectral Constituents (p. 263). The spectral expansion codes indicating the
signs chosen by BEAMST for both the chord and brace member spectral stresses are appended to the
loadcase number in the unity check report, the code for the chord member being appended first.
Each of the 8 spectral expansions are applied to the dynamic chord forces before they are combined
with the static forces the worst cases Qf factor for the joint to determine.
If the dynamic axial force is not of a sufficient magnitude that it can change the combined brace axial
forces direction then a single design is undertaken with the axial force assigned to each joint type being
determined by the static cases proportions.
If the magnitude is sufficient to change the axial force direction, a second analysis is performed; again
the axial force is proportioned by the joint types determined with the static case. The unity checks are
compared and the conservative case is selected. Because force directions are not available for the dynamic case the joint type assignments may be incorrect, hence it may be preferable to override this
function by using the TYPE command.
5.4. API Punching Shear Joint Check (API WSD PUNC)
This section discusses the following topics:
5.4.1. API WSD PUNC Overview
5.4.2. API Punching Shear Check Report
5.4.3. API WSD PUNC Nomenclature
5.4.4. API Allowable Punching Shear Stresses and Unity Checks
5.4.5. Spectral Expansion for Joint Checks (API PUNC)
5.4.1. API WSD PUNC Overview
The API WSD PUNC command in BEAMST requests that punching shear calculations be performed to
API recommendations for tubular joints (Ref. 2). The joints may consist of TUBE elements and/or other
beam types that have been assigned tubular sections in the structural analysis.
Joints for punching shear post-processing are selected using the JOINt command in BEAMST which
specifies the node numbers at joint positions. All joints are assumed ‘simple’. Elements may be excluded
from the joint punching shear check using the SECOndary command.
Joints are automatically classed as K, T or Y depending on the joint geometry as follows:
1. The chord member is the member with the greatest outside diameter.
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BEAMST API Theory
2. If two or more potential chord members have equal diameters; BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
3. In the case of two or more potential chord members with equal diameters and wall thicknesses, the first
two encountered as shown in the Cross Check Report will be considered.
4. If the CHORd command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
BEAMST selects ‘simple’ joint (brace-chord pair) ‘types’ as follows:
1. Brace members ‘perpendicular’ to the chord members (smaller included angle less than or equal to 80
degrees) as T joints.
2. Single non-‘perpendicular’ braces are classified as Y joints. Two non-perpendicular braces on the same
side of the chord are classified as K joints.
3. Cross or Double(DT) joints must be user specified.
4. In the case of user defined K and X joints, no search is performed for a second brace member in the
same brace-chord plane as the first brace.
5. Brace members specified on joint TYPE commands are automatically selected as braces in the above
brace-chord member selection process.
6. No conflict between CHORd command specified members and brace members specified on joint TYPE
commands is allowed.
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHOR commands. Interpolated joint
classifications may be defined using the TYPE command. For K joints a gap dimension appropriate to
the joint may be specified in the TYPE command. A default gap dimension may be specified using the
GAPD command.
The detailed joint punching shear unity check report provides information on joint geometric parameters,
type, acting chord and brace stresses, punching shear, Qf and Qq factors, punching shear allowable(s),
and unity checks. This may be requested using the PRINt UNCK command. The maximum unity check
is flagged for ease of reference. When an interpolatory joint type classification is being employed two
sets of punching shear allowables are reported, one for each joint classification type and these pertain
to joints classified as 100% of the respective joint types.
Summary report 3 comprises the highest unity check for each selected loadcase for each joint.
Summary report 4 comprises the three worst unity checks for each selected joint, together with the
distribution of unity check values. This distribution provides information on the number of unity checks
exceeding an upper limit (default 1.0), less than a lower limit (default 0.5), and the number in the mid
range.
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API Punching Shear Joint Check (API WSD PUNC)
BEAMST commands applicable to the API punching stress command are given in Table 5.6: API WSD
PUNC Commands (p. 243) below and are described in detail in BEAMST Command Reference (p. 51). An
example data file is given in Example 5.4: Example API WSD PUNC data file (p. 244).
For the purpose of simulating joint locally thickened tubulars or joint cans a STUB command is available
for redefinition of member outer diameters and wall thicknesses at the joint.
To calculate allowable punching shear stress to API procedures member yield strengths must be specified
and a YIELd command must be included for this purpose.
The one third increase in basic allowable punching shear stress permitted by the API recommendation
for design extreme environmental conditions can be requested on a loadcase basis using the EXTReme
command in BEAMST. For earthquake (seismic) loadcases a larger increase in basic allowable punching
shear is permitted and the QUAK command will select it for the loadcases specified.
Table 5.6: API WSD PUNC Commands
Command
Description
Usage
Note
API WSD
PUNC
API Punching shear joint check header command
C
UNIT
Units of length and force
YIEL
Yield stress
JOIN
Joint numbers to be reported
TYPE
Joint type and brace element definition
CHOR
Chord elements at a joint
SECO
Secondary members to be ignored in checks
DESI
Defines design section properties
GAPD
Defines default gap dimensions
PROF
Section profiles for use in design
STUB
Tubular member end stub dimensions
CASE
Basic loadcases to be reported
C
2
COMB
Define a combined loadcase for processing
C
2
CMBV
Define a combined loadcase for processing
C
2
SELE
Select/redefine a combined/basic loadcase
title
1
C
SPEC
RENU
Loadcases originating from response spectrum analysis
QUAK
Renumber a basic loadcase
EXTR
Loadcases with earthquake permitted overstress
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Command
Description
Usage
Note
Loadcases allowing extreme loading overstress
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 5.4: Example API WSD PUNC data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
API ED20 PUNC
*
* Investigate all joints in the model except where
* only one element is connected
*
JOINT ALL
NOT JOINTS 1315 1355 5110 5150
*
* Ignore dummy elements
*
SECONDARY ELEMENTS 801 802
UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Indicate that these loadcases are extreme events
*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Specify the chord elements for one of the joints
*
CHORD 1130 122 123
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API Punching Shear Joint Check (API WSD PUNC)
*
* Set some joints as being Y
*
TYPE.OF.JOINT 1130 Y 102
TYPE.OF.JOINT 1130 Y 103
*
* Ask explicitly for all reports
*
PRIN XCHK UNCK SUNI N MM SUM3 BOTH SUM4 BOTH
END
STOP
5.4.2. API Punching Shear Check Report
The final column of each report is reserved for messages. These may be summarized as follows:
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
NO
UNI
Brace angle θ is less than 20 degrees so no unity checks are calculated
CHK
BTA
GT
β ratio is greater than unity so no unity checks are calculated
ONE
+
Largest unity check
N
If the first combined unity check exceeds unity (UCBN), then the second unity check cannot be calculated
(UCCO).
5.4.3. API WSD PUNC Nomenclature
API WSD PUNC uses the following nomenclature:
5.4.3.1. API WSD PUNC Nomenclature - Dimensional
5.4.3.2. API WSD PUNC Nomenclature - Acting Section Forces and Stresses
5.4.3.3. API WSD PUNC Nomenclature - Allowable Stresses and Unity Checks
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5.4.3.1. API WSD PUNC Nomenclature - Dimensional
D
Chord diameter
d
Brace diameter
R
Chord radius
T
Chord thickness
t
Brace thickness
γ
Ratio between the chord radius and thickness R/T
τ
Ratio between the thickness of the brace and chord t/T
θ
Angle between brace and chord
β
Ratio between the diameter of the brace and chord d/D
g
K joint gap
5.4.3.2. API WSD PUNC Nomenclature - Acting Section Forces and Stresses
vp
Acting punching shear (1 each for axial, in-plane and out-of-plane bending)
faxc
Chord axial stress component
fipc
Chord in-plane bending stress
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API Punching Shear Joint Check (API WSD PUNC)
fopc
Chord out-of-plane bending stress
fa
Brace axial stress component
fip
Brace in-plane bending stress
fop
Brace out-of-plane bending stress
fb
Resultant brace bending stress
5.4.3.3. API WSD PUNC Nomenclature - Allowable Stresses and Unity Checks
fyb
Brace yield stress
fyc
Chord yield stress
Vp
Allowable punching shear (1 each for axial, in-plane and out-of-plane bending components)
UCax
Axial punching shear unity check
UCip
In-plane bending punching shear unity check
UCop
Out-of-plane bending punching shear unity check
UCBN
Combined bending punching shear unity check
UCCO
Combined axial and bending punching shear unity check
UCjt
Joint strength unity check
5.4.4. API Allowable Punching Shear Stresses and Unity Checks
This section discusses the following topics:
5.4.4.1. API Allowable - Acting Punching Shear Vp
5.4.4.2. API Allowable - Chord Design Factor Qf
5.4.4.3. API Allowable - Geometry and Load Factor Qq
5.4.4.4. API WSD - Allowable Punching Shear Vp
5.4.4.5. API WSD - Punching Shear Unity Checks
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5.4.4.6. API WSD - Combined Axial and Bending Stress Unity Checks
5.4.4.7. API WSD - Joint Strength Unity Check
5.4.4.1. API Allowable - Acting Punching Shear Vp
Clause/(Eqn)
Commentary
Message
5.4.4.2. API Allowable - Chord Design Factor Qf
Clause/(Eqn)
Commentary
Message
5.4.4.3. API Allowable - Geometry and Load Factor Qq
Clause/(Eqn)
248
Commentary
Message
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API Punching Shear Joint Check (API WSD PUNC)
Clause/(Eqn)
Commentary
Message
If the loadcase is classified as EARTHQUAKE and the
stresses in the chord result from a combination of static
and spectral loadcases, the spectral stress component is
multiplied by a factor of 2. If, however, the resulting
maximum stress (fa + fb) exceeds the yield stress, the
stress components fa, fip, fop are factored such that fa +
fb = fy and thus represent the capacity of the join chord
away from the joint. The factored stresses are printed in
the output report. (Clause 2.3.6e para 1).
5.4.4.4. API WSD - Allowable Punching Shear Vp
Clause/(Eqn)
Commentary
Message
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5.4.4.5. API WSD - Punching Shear Unity Checks
Clause/(Eqn)
Commentary
Message
5.4.4.6. API WSD - Combined Axial and Bending Stress Unity Checks
Clause/(Eqn)
Commentary
Message
If an interpolatory joint type classification is specified
two sets of geometry and loading factors Qq are calculated (Qq1 and Qq2). Two corresponding sets of API
punching shear allowables are then calculated where
each assumes the joint to be 100% of the respective
types. If the joint is specified as C% joint type 1, the
axial unity check is calculated as:
with UCip and UCop being calculated in a similar manner.
The combined unity checks are calculated as before using
the interpolated unity check values corresponding to
each component of stress.
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API Punching Shear Joint Check (API WSD PUNC)
5.4.4.7. API WSD - Joint Strength Unity Check
Clause/(Eqn)
Commentary
Message
5.4.5. Spectral Expansion for Joint Checks (API PUNC)
In response spectrum analysis using modal superposition (Ref. 12) structure displacements and forces
calculated represent estimated maxima. Such estimated maxima are, in general, unsigned (positive).
For the purpose of checking joints to API, a series of worst static-spectral possible loadcases must be
generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depends upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition. Any joint type identification dependant on
axial load is carried out prior to any combinations with dynamic cases.
There are eight possible unique combinations of signs, or ‘spectral expansions’, which can be applied
to unsigned spectral axial and local bending stresses:
2 - axial (tension and compression)
x
2 - local Y bending (hog and sag)
x
2 - local Z bending (hog and sag)
and each is denoted by a single alphabetic letter code in BEAMST in the range R-Y as shown in Figure 5.1: Automatic Signed Spectral Expansion Codes for Joint Checks and the Respective Signs Applied
to Chord/Brace Unsigned Spectral Constituents (p. 252). The spectral expansion codes indicating the
signs chosen by BEAMST for both the chord and brace member spectral stresses are appended to the
loadcase number in the unity check report, the code for the chord member being appended first.
In general the influence of both the chord and brace members’ acting stress is such that by maximizing
the total acting chord and brace stresses the resulting unity check values are also maximized. In such
cases BEAMST adopts the chord and brace member spectral axial and local bending stresses of the
same sign as the static axial and local bending static stresses respectively. There is one condition in
which the above does not hold and this may be summarized as follows:
If when the above procedure is followed and all extreme fibers in the chord are in tension, Qf is set to
unity. In such cases BEAMST searches for a spectral expansion which causes the largest compressive
extreme fiber stress and adopts it if found. This allows a smaller value of Qf to be calculated thus minimizing the allowables.
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BEAMST API Theory
Figure 5.1: Automatic Signed Spectral Expansion Codes for Joint Checks and the Respective Signs
Applied to Chord/Brace Unsigned Spectral Constituents
Notes
Spectral expansion Z represents the trivial case of static components only in a static-spectral loadcase.
5.5. API Nominal Load Check (API WSD NOMI)
This section discusses the following topics:
5.5.1. API WSD NOMI Overview
5.5.2. API Nominal Load Check Report
5.5.3. API WSD NOMI Nomenclature
5.5.4. API Allowable Nominal Loads and Unity Checks
5.5.5. Spectral Expansion for Joint Checks (API NOMI)
5.5.1. API WSD NOMI Overview
The API WSD NOMI command requests that a nominal load joint check be performed as an alternative
to the API punching shear check and both are designed to give equivalent results. The nominal load
check differs from the punching shear check in that allowables are expressed in terms of brace loads
rather than stresses and the factor Qu replaces Qq. The two checks may be performed by interchanging
PUNC and NOMI in the API header command.
The joints may consist of TUBE elements and/or other beam types that have been assigned tubular
sections in the structural analysis.
Joints for punching shear post-processing are selected using the JOINt command in BEAMST which
specifies the node numbers at joint positions. All joints are assumed ‘simple’. Elements may be excluded
from the joint punching shear check using the SECOndary command.
Joints are automatically classed as K, T or Y depending on the joint geometry as follows:
1. The chord member is the member with the greatest outside diameter.
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API Nominal Load Check (API WSD NOMI)
2. If two or more potential chord members have equal diameters; BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
3. In the case of two or more potential chord members with equal diameters and wall thicknesses, the first
two encountered as shown in the Cross Check Report will be considered.
4. If the CHORd command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
BEAMST selects ‘simple’ joint (brace-chord pair) ‘types’ as follows:
1. Brace members ‘perpendicular’ to the chord members (smaller included angle less than or equal to 80
degrees) as T joints.
2. Single non-‘perpendicular’ braces are classified as Y joints. Two non-perpendicular braces on the same
side of the chord are classified as K joints.
3. Cross or Double(DT) joints must be user specified.
4. In the case of user defined K and X joints, no search is performed for a second brace member in the
same brace-chord plane as the first brace.
5. Brace members specified on joint TYPE commands are automatically selected as braces in the above
brace-chord member selection process.
6. No conflict between CHORd command specified members and brace members specified on joint TYPE
commands is allowed.
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHORd commands. Interpolated joint
classifications may be defined using the TYPE command. For K joints a gap dimension appropriate to
the joint may be specified in the TYPE command. A default gap dimension may be specified using the
GAPD command.
The detailed joint punching shear unity check report provides information on joint geometric parameters,
type, acting chord and brace stresses, punching shear, Qf and Qq factors, punching shear allowable(s),
and unity checks. This may be requested using the PRINt UNCK command. The maximum unity check
is flagged for ease of reference. When an interpolatory joint type classification is being employed two
sets of punching shear allowables are reported, one for each joint classification type and these pertain
to joints classified as 100% of the respective joint types.
Summary report 3 comprises the highest unity check for each selected loadcase for each joint.
Summary report 4 comprises the three worst unity checks for each selected joint, together with the
distribution of unity check values. This distribution provides information on the number of unity checks
exceeding an upper limit (default 1.0), less than a lower limit (default 0.5), and the number in the mid
range.
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BEAMST API Theory
BEAMST commands applicable to the API punching stress command are given in Table 5.7: API WSD
NOMI Commands (p. 254) below and are described in detail in BEAMST Command Reference (p. 51). An
example data file is given in Example 5.5: Example of an API WSD NOMI data file (p. 255).
Table 5.7: API WSD NOMI Commands
Command
Description
Usage
API WSD
NOMI
API Nominal load joint check header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
JOIN
Joint numbers to be reported
TYPE
Joint type and brace element definition
CHOR
Chord elements at a joint
SECO
Secondary members to be ignored in checks
DESI
Defines design section properties
GAPD
Defines default gap dimensions
PROF
Section profiles for use in design
STUB
Tubular member end stub dimensions
CASE
Basic loadcases to be reported
C
2
COMB
Define a combined loadcase for processing
C
2
CMBV
Define a combined loadcase for processing
C
2
SELE
Select/redefine a combined/basic loadcase
title
SPEC
RENU
Loadcases originating from response spectrum analysis
QUAK
Renumber a basic loadcase
EXTR
Loadcases with earthquake permitted overstress
Loadcases allowing extreme loading overstress
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
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API Nominal Load Check (API WSD NOMI)
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 5.5: Example of an API WSD NOMI data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
API ED20 NOMI
*
* Investigate all joints in the model except where
* only one element is connected
*
JOINT ALL NOT JOINTS 1315 1355 5110 5150
*
* Ignore dummy elements
*
SECONDARY ELEMENTS 801 802 UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Indicate that these loadcases are extreme events
*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Specify the chord elements for one of the joints
*
CHORD 1130 122 123
*
* Set some joints as being Y
*
TYPE.OF.JOINT 1130 Y 102
TYPE.OF.JOINT 1130 Y 103
*
* Ask explicitly for all reports
*
PRIN XCHK UNCK SUNI N MM SUM3 BOTH SUM4 BOTH
END
STOP
5.5.2. API Nominal Load Check Report
The detailed nominal load unity check report provides information on joint geometric parameters, type,
acting chord and brace loading, Qf, and Qu factors, nominal load allowables and unity checks. This may
be requested using the PRINt UNCK command. The maximum unity check is flagged for ease of reference.
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BEAMST API Theory
When an interpolatory joint type classification is being employed, two sets of nominal load allowables
are reported, one for each joint classification type, and these pertain to joints classified as 100% of the
respective joint types.
The final column of each report is reserved for messages. These may be summarized as follows:
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
NO
UNI
Brace angle θ is less than 20 degrees so no unity checks are calculated.
CHK
BTA
GT
β ratio is greater than unity so no unity checks are calculated.
ONE
+
Largest unity check.
N
If the first combined unity check exceeds unity (UCBN) then the second unity check cannot be calculated
(UCCO).
5.5.3. API WSD NOMI Nomenclature
API WSD NOMI uses the following nomenclature:
5.5.3.1. API WSD NOMI Nomenclature - Dimensional
5.5.3.2. API WSD NOMI Nomenclature - Acting Forces and Stresses
5.5.3.3. API WSD NOMI Nomenclature - Allowable Stresses and Unity Checks
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API Nominal Load Check (API WSD NOMI)
5.5.3.1. API WSD NOMI Nomenclature - Dimensional
D
Chord diameter
d
Brace diameter
R
Chord radius
T
Chord thickness
t
Brace thickness
γ
Ratio between the chord radius and thickness R/T
τ
Ratio between the thickness of the brace and chord t/T
θ
Angle between brace and chord
β
Ratio between the diameter of the brace and chord d/D
g
K joint gap
5.5.3.2. API WSD NOMI Nomenclature - Acting Forces and Stresses
P
Brace axial force
Mip
Brace in-plane bending moment
Mop
Brace out-of-plane bending moment
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BEAMST API Theory
faxc
Chord axial stress component
fipc
Chord in-plane bending stress
fopc
Chord out-of-plane bending stress
fa
Brace axial stress component
fip
Brace in-plane bending stress
fop
Brace out-of-plane bending stress
fb
Resultant brace bending stress
5.5.3.3. API WSD NOMI Nomenclature - Allowable Stresses and Unity Checks
fyc
Chord yield stress
Pa
Allowable axial force
Maip
Allowable in-plane bending moment
Maop
Allowable out-of-plane bending moment
UCax
Axial force unity check
UCip
In-plane bending unity check
UCop
Out-of-plane bending unity check
UCBN
Combined bending unity check
UCCO
Combined axial and bending unity check
UCjt
Joint strength unity check
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API Nominal Load Check (API WSD NOMI)
5.5.4. API Allowable Nominal Loads and Unity Checks
This section discusses the following topics:
5.5.4.1. API Allowable - Chord Design Factor Qf
5.5.4.2. API Allowable - Ultimate Strength Factor Qu
5.5.4.3. API Allowable - Allowable Nominal Loads
5.5.4.4. API WSD - Nominal Load Unity Checks
5.5.4.5. API WSD - Combined Axial and Bending Unity Checks
5.5.4.6. API WSD - Interpolated Joints
5.5.4.7. API WSD - Joint Strength Unity Check
5.5.4.1. API Allowable - Chord Design Factor Qf
Clause/(Eqn)
Commentary
Message
5.5.4.2. API Allowable - Ultimate Strength Factor Qu
Clause/(Eqn)
Commentary
Message
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259
BEAMST API Theory
Clause/(Eqn)
Commentary
Message
If the loadcase is classified as EARTHQUAKE and the
stresses in the chord result from a combination of static
and spectral loadcases, the spectral stress component is
multiplied by a factor of 2. If, however, the resulting
maximum stress (fa + fb) exceeds the yield stress, the
stress components fa, fip, fop are factored such that fa +
fb = fy and thus represent the capacity of the join chord
away from the joint. The factored stresses are printed in
the output report. (Clause 2.3.6e para 1).
5.5.4.3. API Allowable - Allowable Nominal Loads
Clause/(Eqn)
260
Commentary
Message
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API Nominal Load Check (API WSD NOMI)
5.5.4.4. API WSD - Nominal Load Unity Checks
Clause/(Eqn)
Commentary
Message
5.5.4.5. API WSD - Combined Axial and Bending Unity Checks
Clause/(Eqn)
Commentary
Message
5.5.4.6. API WSD - Interpolated Joints
Clause/(Eqn)
Commentary
Message
If an interpolatory joint type classification is specified,
two sets of geometry and loading factors Qu are calculated (Qu1 and Qu2). Two corresponding sets of nominal
load allowables are then computed where each assumes
the joint to be 100% of the respective types. If the joint
is specified as C% joint type 1, the axial unit check is
calculated as:
with UCip and UCop being calculated in a similar manner.
The combined unity checks are calculated as before using
the interpolated unity check values corresponding to
each component of stress.
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BEAMST API Theory
5.5.4.7. API WSD - Joint Strength Unity Check
Clause/(Eqn)
Commentary
Message
5.5.5. Spectral Expansion for Joint Checks (API NOMI)
In response spectrum analysis using modal superposition (Ref. 12) structure displacements and forces
calculated represent estimated maxima. Such estimated maxima are, in general, unsigned (positive).
For the purpose of checking joints to API, a series of worst static-spectral possible loadcases must be
generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depends upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition. Any joint type identification dependant on
axial load is carried out prior to any combinations with dynamic cases.
There are eight possible unique combinations of signs, or ‘spectral expansions’, which can be applied
to unsigned spectral axial and local bending stresses:
2 - axial (tension and compression)
x
2 - local Y bending (hog and sag)
x
2 - local Z bending (hog and sag)
and each is denoted by a single alphabetic letter code in BEAMST in the range R-Y as shown in Figure 5.2: Automatic Signed Spectral Expansion Codes for Joint checks and the Respective Signs Applied
to Chord/Brace Unsigned Spectral Constituents (p. 263). The spectral expansion codes indicating the
signs chosen by BEAMST for both the chord and brace member spectral stresses are appended to the
loadcase number in the unity check report, the code for the chord member being appended first.
In general the influence of both the chord and brace members’ acting stress is such that by maximizing
the total acting chord and brace stresses the resulting unity check values are also maximized. In such
cases BEAMST adopts the chord and brace member spectral axial and local bending stresses of the
same sign as the static axial and local bending static stresses respectively. There is one condition in
which the above does not hold and this may be summarized as follows:
If a cross joint is specified two values of the axial components of Qq/Qu may be calculated depending
on whether the axial stress in the brace is compressive or tensile. If a large spectral axial stress is to be
combined with a small tensile static stress it is not obvious which spectral expansion leads to the worst
unity check value. A small compressive axial stress may produce a smaller allowable than a higher tensile
stress. BEAMST considers both possibilities and adopts a spectral expansion which leads to the worst
unity check.
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
Figure 5.2: Automatic Signed Spectral Expansion Codes for Joint checks and the Respective Signs
Applied to Chord/Brace Unsigned Spectral Constituents
Notes
Spectral expansion Z represents the trivial case of static components only in a static-spectral loadcase.
5.6. API Load and Resistance Factor Design Allowable Member Stress
Check (API LRFD MEMB)
This section discusses the following topics:
5.6.1. API LRFD MEMB Overview
5.6.2. API LRFD MEMB Unity Check Report
5.6.3. API LRFD MEMB Nomenclature
5.6.4. API LRFD Allowable Stresses and Unity Checks
5.6.5. Spectral Loadcases
5.6.1. API LRFD MEMB Overview
The API LRFD MEMB header command in BEAMST is used to request member stress checks to API LRFD
design recommendations (Ref. 3) for TUBE elements or other beam types that have been assigned tubular sections in the structural analysis.
Unstiffened tubular local buckling, allowable stresses taking into account inelastic shell buckling,
member buckling and yield strength and unity checks are all performed to the API recommendations
as detailed in API LRFD Allowable Stresses and Unity Checks (p. 271). Amplification-reduction factors,
Cmy and Cmz, are restricted to a maximum of 0.85 unless these values are user defined. TUBE element
effective shear areas are rigidly restricted to one half of the cross-section area.
The API specification is written in terms of member yield strengths, so a YIELd command must be used
to specify the yield strength.
Members may be selected for processing by elements and/or groups. The member section information
may be redefined using DESI commands. Further commands are available for defining topological
characteristics of the members (EFFE, UNBR and ULCF) and specifying members that are classified as
‘secondary’ (SECO).
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BEAMST API Theory
The SECT command may be used to define intermediate points along a member at which member
forces are to be evaluated, checked and reported. These are in addition to results automatically printed
at the member end points and positions of any step change in cross-section properties. Alternatively
the SEARch command may be used which requests that moments and stresses are to be evaluated at
specified locations along the beam but to be reported only if they give a maximum force, stress or
utilization. These extra locations are in addition to those selected using the SECT command.
The API LRFD standard utilizes limit state checks with resistance coefficients to achieve the desired level
of safety. In keeping with this principle, applied loads must be multiplied by appropriate factors, as
defined in the code of practice (Section C, Loads), to develop the design load case combinations necessary
for processing. Where non-linear pile analysis is undertaken (using SPLINTER) the design loads must be
applied to the pile model to account for the increased non-linearity this introduces. In situations where
a non-linear pile analysis has not been carried out, the design loads may be produced using the COMB
or CMBV commands utilizing the required load factors. For abnormal loading conditions the ABNO
command may be used to set the resistance coefficients to unity.
The selection of output reports is made using the PRIN command with the appropriate parameters for
the required reports. The PRIN command is also used to request the various summary reports available.
Two summary reports are available>
Summary report 1 is requested with the PRIN SUM1 subcommand and details the loadcase producing
the highest unity check value for each element.
Summary report 3 is requested with the PRIN SUM3 subcommand and consists of the highest unity
check for each selected loadcase for each element selected.
A complete list of the command set available for the API LRFD MEMB code checks is given in Table 5.8: API
LRFD MEMB Commands (p. 264) below and described in detail in BEAMST Command Reference (p. 51).
An example data file is given in Example 5.6: Example of API LRFD MEMB data file (p. 265).
Table 5.8: API LRFD MEMB Commands
Command
Description
Usage
API LRFD
MEMB
API allowable stress header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SEAR
Search other sections in addition to those
requested on the SECT command for maximum forces and stresses
SECO
Secondary members
DESI
Defines design section properties
PROF
Section profiles for use in design
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
Command
Description
EFFE
Effective lengths/factors
CB
Pure bending Cb coefficient
CMY/CMZ
Amplification reduction factors Cmy/Cmz
UNBR
Unbraced lengths of element
ULCF
Unbraced length of compression flange
ABNO
Abnormal loadcases
CASE
Basic loadcases to be reported
COMB
Define a combined loadcase for processing
CMBV
Define a combined loadcase for processing
SELE
Select/redefine a combined/basic loadcase
title
Usage
Note
C C C
3
3
3
SPEC
RENU
Basic loadcases from response spectrum
analysis
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. At least one CASE, CMBV or COMB command must be included.
Example 5.6: Example of API LRFD MEMB data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
UNIT KN M
OPTION GOON
END
API LRFD ED1 MEMB
*
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265
BEAMST API Theory
* Horizontal plan bracing level -50 m
*
GROU 1
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.35 1 1.1 3 1.1 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.35 2 1.1 3 1.1 4
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main plan bracing members use effective length
* coefficient of 0.8
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFE 0.8 ELEM 105 106
EFFE 0.8 ELEM 101 TO 104
EFFE 0.8 ELEM 107 TO 110
EFFE 1.0 GROU 1
*
* Out of plane unbraced lengths need redefining
*
UNBR FACT 2.0 1.0 ELEM 105 106
UNBR LENG 15.0 7.5 ELEM 102 103
*
* Override program computed moment amplification RF
*
CMY 0.85 ELEM 102 103 105 106
CMZ 0.85 ELEM 102 103 105 106
*
* Check mid-span sections
*
SECT 0.5 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 BOTH SUM3
END
STOP
5.6.2. API LRFD MEMB Unity Check Report
The unity check report is presented on an element by element basis. The header line displays the element
number, the associated node numbers, the element group number and the units in use. The results are
printed for each of the selected positions (or sections) on the element for each loadcase in turn. The
first columns of the report define the loadcase, section number and position as a ratio of the elements
length together with the section diameter and thickness, slenderness ratios and the column slenderness
parameter (λ).
The next two columns present the acting axial, shear and bending stresses pertaining to the given
loadcase.
The allowable stresses for axial, shear and bending (in local Y and Z axes) stresses are presented in the
next columns of the report together with the Euler buckling strengths (Fey and Fez), the reduced yield
stress for local and column buckling interaction and the inelastic buckling strength. These are preceded
by an alpha- numeric descriptor (CODE) that indicates the derivation of each of the main allowable
stresses. These descriptors are of the form:
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
T.XVYZ or C.XVYZ
T or C defines whether the member is in tension or compression, XVYZ are individual alpha codes which
relate to the axial(X), shear(V), and bending(Y,Z) allowable stresses. These alpha codes specify the design
code clause or equation used to evaluate the allowable stresses and are defined in Table 5.9: API LRFD
MEMB Allowable Stress Alphabetic Codes (p. 267).
Table 5.9: API LRFD MEMB Allowable Stress Alphabetic Codes
Stress
Code
Clause
X
A
AISC LRFD B7
B
AISC LRFD B7
C
(D.2.2-2a)
E
(D.2.2-2b)
V
Y
(D.2.4-1)
Y
C
(D.2.3-2a)
Z
G
(D.2.3-2b)
H
(D.2.3-2c)
Description
shear yield
For example, the unity check CODE combination
C.CYCC
indicates that the member is in compression and that the following clause/equations were used to derive
the allowable stresses:
The last two characters are always the same for tubular members.
The allowable stresses are followed by the nine utilization values for axial, shear, torsion, bending (y,z
and resultant) and the combined yield and buckling checks.
The final column of the table, headed Messages, flags all lines of results where any of the checks have
failed. These messages may be summarized as follows:
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FAIL
Member has a utilization exceeding unity or fails parameter limits (flagged with THKF, DTRF, YIEL, SLRF,
SLRW or SHYF).
PNT9
Unity check value exceeds 0.9.
THKF
Wall thickness less than 6 mm.
DTRF
Allowed diameter thickness ratio exceeded (D/t >= 300).
YIEL
Yield stress greater than 414 MPa.
SLRF
Slenderness ratio greater than 200 for a compression member.
SLRW
Slenderness ratio greater than 300 for a tension member.
SHYF
Shear yielding failure.
5.6.3. API LRFD MEMB Nomenclature
API LRFD MEMB uses the following nomenclature:
5.6.3.1. API LRFD MEMB Nomenclature - Dimensional
5.6.3.2. API LRFD MEMB Nomenclature - Acting Section Stresses
5.6.3.3. API LRFD MEMB Nomenclature - Allowable Stresses and Unity Checks
5.6.3.4. API LRFD MEMB Nomenclature - Parameters
5.6.3.1. API LRFD MEMB Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
k
Effective length factor (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
L
Unbraced length of member (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
r
Radius of gyration (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
S
Elastic section modulus
Z
Plastic section modulus
5.6.3.2. API LRFD MEMB Nomenclature - Acting Section Stresses
fa
Axial stress
fby, fbz
Bending stresses about y and z
fc
Axial compressive stress
fv
Maximum shear stress
5.6.3.3. API LRFD MEMB Nomenclature - Allowable Stresses and Unity Checks
fy
Yield stress
f1y
Reduced yield stress accounting for interaction of local and column buckling
Fxc
Inelastic local buckling stress
Fa
Allowable axial compressive stress
Ft
Allowable axial tensile stress
Fb
Allowable bending stress
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Fv
Allowable flexural shear stress
Fvt
Allowable torsional shear stress
Fey, Fez
Euler strength for y and z axes
Fxe
Elastic local buckling strength
Fcn
Nominal axial compressive strength
Fbn
Nominal bending strength
Fha
Allowable elastic hoop buckling stress
Fca
Allowable inelastic axial local buckling stress
Fxa
Allowable elastic axial local buckling stress
UCax
Axial unity check
UCvmax
Flexural shear unity check
UCTOR
Torsional shear unity check
UCby
Pure bending check about y axis
UCbz
Pure bending check about z axis
UCbr
Pure resultant bending check
UCbu
Combined axial compression and bending buckle check
UCy1
Combined axial and bending yield unity check (D.3.2-2)
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
UCy2
Combined axial and bending yield unity check (D.3.2-3)
UCCSR
Upper bound member buckling unity check
5.6.3.4. API LRFD MEMB Nomenclature - Parameters
E
Young's modulus
Cmy, Cmz
Moment amplification reduction factors
φb
Resistance factor for bending
φc
Resistance factor for axial compressive strength
φt
Resistance factor for axial tensile strength
φv
Resistance factor for shear
5.6.4. API LRFD Allowable Stresses and Unity Checks
This section discusses the following topics:
5.6.4.1. API LRFD Partial Coefficients
5.6.4.2. API LRFD - Allowable Tension Stress, Ft
5.6.4.3. API LRFD - Allowable Compression Stress, Fa
5.6.4.4. API LRFD - Allowable Bending Stress, Fb
5.6.4.5. API LRFD Allowable Shear Stress, Fv and Fvt
5.6.4.6. API LRFD MEMB - Unity Checks
5.6.4.7. API LRFD MEMB - Combined Stresses
5.6.4.1. API LRFD Partial Coefficients
Clause/(Eqn)
Commentary
Code Message
Resistance factors
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BEAMST API Theory
Clause/(Eqn)
Commentary
Code Message
These factors may be set to unity by utilizing the
ABNO command.
Load coefficients
BEAMST assumes the appropriate factors have
already been applied by the user.
5.6.4.2. API LRFD - Allowable Tension Stress, Ft
Clause/(Eqn)
Commentary
Code Message
Allowable stress
Limiting Slenderness Ratio
5.6.4.3. API LRFD - Allowable Compression Stress, Fa
Clause/(Eqn)
272
Commentary
Code Message
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
Clause/(Eqn)
Commentary
Code Message
5.6.4.4. API LRFD - Allowable Bending Stress, Fb
Clause/(Eqn)
Commentary
Code Message
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Clause/(Eqn)
Commentary
Code Message
5.6.4.5. API LRFD Allowable Shear Stress, Fv and Fvt
Clause/(Eqn)
Commentary
Code Message
Beam Shear
Torsional Shear
5.6.4.6. API LRFD MEMB - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
274
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
Clause/(Eqn)
Commentary
Code Message
Shear
Pure Bending
5.6.4.7. API LRFD MEMB - Combined Stresses
Clause/(Eqn)
Commentary
Code Message
Axial compression and bending buckle check
For axial tension and bending buckle check
UCbu is set = 0.0
Combined axial and bending yield check
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Clause/(Eqn)
Commentary
Code Message
Buckle CSR check
UCCSR
This uses the same equation (D.3.2-1) as the axial
compression and bending buckle check but
utilizes the maximum stresses and the minimum
member properties occurring along the member
in order to compute an upper bound buckle
check. It should be noted that this check often
results in high utilization ratios which may not
occur in practice, but indicates a need to undertake a more rigorous hand analysis of the member.
5.6.5. Spectral Loadcases
In response spectrum analysis using modal superposition (Ref. 12) the structure displacements and
forces calculated represent estimated maxima and are, in general, unsigned (positive).
For the purpose of checking members to API a series of worst case static-spectral loadcase permutations
must be generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depend upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition.
5.6.5.1. Torsional Effects
The maximum torsional spectral load contribution at each beam section position is deduced in a similar
manner to the axial load contribution in 5.6.5.2.
5.6.5.2. Axial Unity Check and the Axial Component of Combined Stress Buckle and
Yield Unity Checks
The maximum axial spectral load contribution at each beam section position is calculated by assuming
that the spectral axial load distribution is linear with both member end loads having the same sign.
The sign adopted for these member spectral end loads is normally assumed to be of the same sign as
the static axial load (if it exists). In cases where the static loadcase is tensile it is possible that reversing
the sign of the spectral case may produce a net compressive load and, hence, a more onerous utilization
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API Load and Resistance Factor Design Allowable Member Stress Check (API LRFD
MEMB)
(since buckling may become a problem). Under these conditions, the checks are repeated with the
spectral axial stresses reversed with respect to the static case, and the combination producing the
highest utilization of both conditions is reported. The sign adopted may be ascertained from the utilization code reported.
As in all checks performed by BEAMST, zero axial stress is treated as compressive (-ve sign, ASAS convention).
5.6.5.3. Local Axes Shear Unity Checks and Maximum Shear Unity Check for Tubular
Sections
In order to be able to generate mid-member stresses an equivalent member spectral loading is required.
BEAMST assumes that the spectral loading consists of a linearly varying inertia loading on the member
acting in a rigid fashion (that is, the load consists of that due to pure translation and rotation of the
member). This inertia loading is calculated by ‘balancing’ it against the member signed spectral end
forces (shears and moments).
For each local bending plane there are sixteen unique signed spectral end force (shears and moments)
expansions/cases of which eight are symmetric, but of opposite sign, to the remaining eight. Each of
these sixteen signed spectral expansions is denoted by a single alphabetic letter code in BEAMST in
the range A-P as shown in Table 5.3: Automatic Signed Spectral Expansion Codes for Member Checks
and the Respective Signs Applied for Bending in the Local Y-Y/Z-Z Planes (p. 220). For spectral loadcases
only eight of the sixteen possible expansions need theoretically be considered but for static-spectral
summations all sixteen have to be taken into account.
The Shear Unity Checks are maximized by adopting the static-spectral signed expansion which maximizes
the total acting shear at each beam section position. For tubular sections the combination of staticspectral expansions which maximizes the resultant acting shear on the cross section and the Maximum
Shear Unity Check.
5.6.5.4. Local Axes Pure Bending Unity Checks and Bending Components of Combined
Stresses Yield and Buckle Unity Checks
Pure bending checks may be based upon the combination of static-spectral expansions which maximize
the bending stress on the cross-section. For the combined buckle check, however, it is necessary to
determine the spectral expansion which maximizes the ratio of acting to allowable stress as opposed
to simply maximizing the acting stress. In general this is necessary because the check includes the
amplification reduction factors Cmy and Cmz which are themselves functions of the signs and relative
magnitudes of the member total end forces.
BEAMST investigates each of the sixteen signed spectral expansions shown in Table 5.3: Automatic
Signed Spectral Expansion Codes for Member Checks and the Respective Signs Applied for Bending in
the Local Y-Y/Z-Z Planes (p. 220) for both of the local axes bending planes for each beam section position
being considered and reports the critical expansions at each section.
5.6.5.5. Unity Check Report for Spectral Cases
The Unity Check Report for a spectral or a static-spectral summation is the same as that for a pure
static case except that the loadcase number is appended with the letters A-P indicating which expanded
case produces the highest overall utilization at the section under consideration.
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5.6.5.6. API Combined Stress Buckle Unity Check (Buckle CSR)
As for the yield unity check it is necessary to determine which spectral expansions maximize the
bending components of the buckle unity check defined by ratio of ‘equivalent uniform bending’ stress
to minimum allowable.
BEAMST investigates all sixteen spectral expansions determining for each expansion the maximum
bending stress and minimum allowable stress occurring anywhere along the beam and the buckle unity
check bending component for the bending plane being considered. Over all sixteen expansions, those
which maximize the bending components in each of the local bending planes are used in the final
buckle check and are reported in the Highest Buckle Unity Check Report.
Note that the CSR value is not normally reported in summary file 1 unless it represents the maximum
utilization for a beam, or the utilization is greater than unity.
5.7. API Load and Resistance Factor Design Hydrostatic Collapse Check
(API LRFD HYDR)
This section discusses the following topics:
5.7.1. API LRFD HYDR Overview
5.7.2. API LRFD Hydrostatic Unity Check Report
5.7.3. API LRFD HYDR Nomenclature
5.7.4. API LRFD - Allowable Stresses and Unity Checks
5.7.1. API LRFD HYDR Overview
The API LRFD HYDR header command is used to request that hydrostatic pressure, allowable stresses,
member actions, unity checks and combined stress hydrostatic collapse unity checks be performed to
API design recommendations (Ref. 3) for TUBE elements, or other beam types that have been assigned
tubular sections in the structural analysis.
Members may be selected for processing by element and/or group. The member section dimensions
may be redefined using DESI commands to modify the diameter and/or thickness. Further commands
are available for defining topological characteristics of the members (EFFE, UNBR and ULCF) and specifying members that are classified as ‘secondary’ (SECO).
The SECT command may be used to define intermediate points along a member at which member
forces are to be evaluated, checked and reported. These are in addition to results automatically printed
at the member end points and positions of any step change in cross-section properties. Alternatively
the SEARch command may be used which requests that moments and stresses are to be evaluated at
specified locations along the beam but to be reported only if they give a maximum force, stress or
utilization. These extra locations are in addition to those selected using the SECT command.
The calculation of hydrostatic pressures requires a knowledge of each member position with respect
to still water level, tide height, wave height and length as well as details of the sea medium and various
commands in BEAMST exist to define these. First a reference frame has to be specified for the (sea)
water axes and its origin position in terms of the jacket reference frame defined (i.e. the global co-ordinate system used in the previous ASAS analysis) using a MOVE command. (See BEAMST Command
Reference (p. 51) and Ref. 14). This command is optional and if omitted the water and jacket frame
origins are taken to coincide. Having defined the water axes origin, the relative orientations of water
and jacket axes must follow. For example the jacket axes may be inclined to the water axes if the jacket
is being considered in a semi-submerged position. In order to convert pressure heads to hydrostatic
pressure the coefficient of gravity in the vertical downwards (-Zwater) water direction is required. If the
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API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
components of this coefficient of gravity are specified in terms of the jacket axes then the water-jacket
axes orientation and the coefficient of gravity can be specified in a single operation. The GRAVity
command in BEAMST is available for this purpose and is compulsory for the API hydrostatic collapse
check. The jacket and water axes are now spatially fixed and the only remaining information required
for calculation of water static head is that of mean water level, sea bed level, density of seawater and
tide height. This information is specified using the compulsory ELEVation command. For completion a
further command WAVE is available for specification of wave height and period, for the inclusion of
wave induced pressure components. This command is optional and if omitted the static water head
only is considered. For calculation
All elements selected for hydrostatic collapse post-processing are assumed to be unflooded and unstiffened (i.e. axial length of cylinder between stiffening rings, diaphragms or end connections is equal
to the element length). This unstiffened length may be defined explicitly using a ULCF command. This
command allows ring stiffened tubulars to be checked for hydrostatic pressure collapse between the
stiffening rings. The API LRFD HYDRcode also includes some of the basic member interaction checks
and use is made of the unbraced lengths (UNBR) and effective length factors (EFFE) together with the
amplification reduction factors Cmy and Cmz. It is important, therefore, that these terms are supplied
in a form compatible with an API LRFD MEMB check.
The API LRFD standard utilizes limit state checks with resistance coefficients to achieve the desired level
of safety. In keeping with this principle, applied loads must be multiplied by appropriate factors, as
defined in the code of practice (Section C, Loads), to develop the design load case combinations necessary
for processing. Where non-linear pile analysis is undertaken (using SPLINTER) the design loads must be
applied to the pile model to account for the increased non-linearity this introduces. In situations where
a non-linear pile analysis has not been carried out, the design loads may be produced using the COMB
or CMBV commands utilizing the required load factors. For abnormal loading conditions the ABNO
command may be used to set the resistance coefficients to unity.
A detailed Unity Check Report incorporating beam section hydrostatic depth, member acting and allowable stresses, membrane hoop and tension/compression collapse interaction unity checks is available
and may be requested using the PRIN UNCK command.
A summary report is also available.
Summary report number 1 is requested using the PRIN SUM1 command and gives the highest unity
check values for each element.
The BEAMST commands applicable to the API LRFD HYDR collapse Command data are given in
Table 5.10: API LRFD HYDR Commands (p. 279) below and are described in detail in BEAMST Command
Reference (p. 51). An example data file is given in Example 5.7: Example API LRFD HYDR data file (p. 281).
Table 5.10: API LRFD HYDR Commands
Command
Description
Usage
API
LRFD
HYDR
API LRFD hydrostatic collapse header command
C
UNIT
Units of length and force
YIEL
Yield stress
Note
1
C
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BEAMST API Theory
Command
Description
Usage
ELEV
Water depth and gravity
C
MOVE
Water axis origin in global structure axis system
C
WAVE
Wave height and period
GRAV
Gravitational acceleration relative to structure axis system
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
DESI
Defines design section properties
PROF
Section profiles for use in design
EFFE
Effective lengths/factors
UNBR
Unbraced lengths of element
ULCF
Length of tubular members between stiffening rings, diaphragms, etc
ABNO
Abnormal loadcases
CASE
Basic loadcases to be reported
COMB
Define a combined loadcase for processing
C
C
C
3
3
3
CMBV
Define a combined loadcase for processing
HYDR
Load factors for design hydrostatic head
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
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C
Note
API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
3. At least one CASE, CMBV or COMB command must be included.
Example 5.7: Example API LRFD HYDR data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
UNIT KN M
END
API LRFD ED1 HYDR
*
* Horizontal plan bracing level -50 m
*
GROU 1
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.35 1 1.1 3 1.1 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.35 2 1.1 3 1.1 4 ** Hydrostatic information
*
ELEVATION 0.0 -50.0 1.025
GRAVITY 0.0 0.0 -9.81
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main plan bracing members use effective length
* coefficient of 0.8
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFE 0.8 ELEM 105 106
EFFE 0.8 ELEM 101 TO 104
EFFE 0.8 ELEM 107 TO 110
EFFE 1.0 GROU 1
*
* Out of plane unbraced lengths need redefining
*
UNBR FACT 2.0 1.0 ELEM 105 106
UNBR LENG 15.0 7.5 ELEM 102 103
*
* Override program computed moment amplification RF
*
CMY 0.85 ELEM 102 103 105 106
CMZ 0.85 ELEM 102 103 105 106
*
* Check mid-span sections
*
SECT 0.5 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 BOTH
END
STOP
5.7.2. API LRFD Hydrostatic Unity Check Report
The final column of each report is reserved for messages. These may be summarized as follows:
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FAIL
Code check failure for this member.
Unity check 1.0 or THKF, YIEL, DTRF
PNT9
Unity check value exceeds 0.9
FXHA
Net axial stress fax less than half allowable elastic hoop stress and thus eqn (D.3.4-3) not checked
DTRF
Allowed diameter thickness ratio exceeded (D/t >= 300)
THXF
Wall thickness less than recommended minimum of 6mm
YIEL
Yield strength greater than 414MPa (60ksi)
MGTR
Geometry parameter, used in the elastic hoop buckling stress, M, greater than 1.6 D/t
NOCK
Section is out of the water and is thus not checked for hydrostatic conditions.
5.7.3. API LRFD HYDR Nomenclature
API LRFD HYDR uses the following nomenclature:
5.7.3.1. API LRFD HYDR Nomenclature - Dimensional
5.7.3.2. API LRFD HYDR Nomenclature - Acting Section Forces and Stresses
5.7.3.3. API LRFD HYDR Nomenclature - Allowable Stresses and Unity Checks
5.7.3.4. API LRFD HYDR Nomenclature - Parameters
5.7.3.1. API LRFD HYDR Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
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API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
k
Effective length factor (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum).
Lu
Unstiffened length of member
L
Unbraced length of member (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
r
Radius of gyration (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
S
Elastic section modulus
Z
Plastic section modulus
5.7.3.2. API LRFD HYDR Nomenclature - Acting Section Forces and Stresses
fh
Hoop stress
ft
Axial tensile stress
fc
Axial compressive stress
fb
Resultant bending stress
fby
Bending stresses about local y axis
fbz
Bending stresses about local z axis
5.7.3.3. API LRFD HYDR Nomenclature - Allowable Stresses and Unity Checks
fy
Yield stress
f1y
Reduced yield stress accounting for interaction of local and column buckling
Fxc
Inelastic local buckling stress
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Fa
Allowable axial compressive stress
Ft
Allowable axial tensile stress
Fb
Allowable bending stress
Fxe
Elastic local buckling strength
Fcn
Nominal axial compressive strength
Fbn
Nominal bending strength
Fha
Allowable elastic hoop buckling stress
Fhc
Critical hoop buckling stress
Fhe
Elastic hoop buckling stress
Fca
Allowable inelastic axial local buckling stress
Fch
Allowable critical hoop buckling stress
Fxa
Allowable elastic axial local buckling stress
UCax
Axial tension unity check
UCbu
Combined axial compression and bending buckle check (D.3.2-1)
UCc
Combined axial (tension or compression), bending and hydrostatic pressure check
UCh
Hoop compressive unity check
UCy
Combined axial compression and bending yield unity check (Maximum of D.3.2-2 and D.3.2-3)
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API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
5.7.3.4. API LRFD HYDR Nomenclature - Parameters
E
Young's modulus
ν
Poisson’s ratio
M
Geometric parameter
Ch
Critical hoop buckling coefficient
φb
Resistance factor for bending
φc
Resistance factor for axial compressive strength
φh
Resistance factor for hoop buckling
φt
Resistance factor for axial tensile strength
5.7.4. API LRFD - Allowable Stresses and Unity Checks
In the hydrostatic collapse check the following assumptions are made:
1. All members are unflooded.
2. Out-of-roundness is assumed to be within API RP2B tolerance limits.
3. Wave crest is assumed to be directly above the beam section position under consideration.
4. Hydrostatic pressure is only considered for beam section positions below the static water level (=mean
water level + tide height + storm surge height).
5. The wave length, Lw, is adequately described by linear wave theory as follows:
a. If
(shallow water)
then
b. Else if
and
(deep water)
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BEAMST API Theory
then
c. Else Lw is obtained iteratively from
where:
• d = static water depth
• g = acceleration due to gravity
• Tw = wave period
5.7.4.1. API LRFD HYDR - Design Hydrostatic Pressure
Clause/(Eqn)
Commentary
Message
5.7.4.2. API LRFD HYDR - Limit Checks
Clause/(Eqn)
286
Commentary
Message
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API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
5.7.4.3. API LRFD HYDR - Elastic Hoop Buckling Stress Fhe
Clause/(Eqn)
Commentary
Message
5.7.4.4. API LRFD HYDR - Allowable Elastic Hoop Buckling Stress Fha
Clause/(Eqn)
Commentary
Message
5.7.4.5. API LRFD HYDR - Critical Hoop Buckling Stress Fhc
Clause/(Eqn)
Commentary
Message
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BEAMST API Theory
Clause/(Eqn)
Commentary
Message
5.7.4.6. API LRFD HYDR - Allowable Critical Hoop Buckling Stress Fch
Clause/(Eqn)
Commentary
Message
5.7.4.7. API LRFD HYDR - Critical Axial Elastic Local Buckling Stress Fxe
Clause/(Eqn)
Commentary
Message
5.7.4.8. API LRFD HYDR - Allowable Axial Elastic Local Buckling Stress Fxa
Clause/(Eqn)
Commentary
Message
5.7.4.9. API LRFD HYDR - Inelastic Axial Local Buckling Stress Fxc
Clause/(Eqn)
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Commentary
Message
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API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
Clause/(Eqn)
Commentary
Message
5.7.4.10. API LRFD HYDR - Allowable Inelastic Axial Local Buckling Stress Fca
Clause/(Eqn)
Commentary
Message
5.7.4.11. API LRFD HYDR - Hoop Compressive Unity Check UCH
Clause/(Eqn)
Commentary
Message
5.7.4.12. API LRFD HYDR - Allowable Tension Stress Ft
Clause/(Eqn)
Commentary
Message
5.7.4.13. API LRFD HYDR - Allowable Axial Compression Stress Fa
Clause/(Eqn)
Commentary
Message
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Clause/(Eqn)
Commentary
Message
5.7.4.14. API LRFD HYDR - Allowable Bending Stress Fb
Clause/(Eqn)
Commentary
Message
5.7.4.15. API LRFD HYDR - Axial Tension Check UCax
Clause/(Eqn)
290
Commentary
Message
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API Load and Resistance Factor Design Hydrostatic Collapse Check (API LRFD HYDR)
Clause/(Eqn)
Commentary
Message
5.7.4.16. API LRFD HYDR - Combined Tension and Hydrostatic Pressure Unity Check
UCc
Clause/(Eqn)
Commentary
Message
5.7.4.17. API LRFD HYDR - Combined Compression and Hydrostatic Pressure Unity
Checks
Clause/(Eqn)
Commentary
Message
Axial compression and bending buckle check
Combined axial compression and bending yield check
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Clause/(Eqn)
Commentary
Message
Combined axial compression and bending yield check
5.8. API Load and Resistance Factor Design Nominal Load Check (API
LRFD JOIN)
This section discusses the following topics:
5.8.1. API LRFD JOIN Overview
5.8.2. API LRFD JOIN Check Report
5.8.3. API LRFD JOIN Nomenclature
5.8.4. API Allowable Nominal Loads and Unity Checks
5.8.5. Spectral Expansion for Joint Checks (API LRFD)
5.8.1. API LRFD JOIN Overview
The API LRFD JOIN command requests that a nominal load joint check be performed to API LRFD design
recommendations (Ref. 3).
The joints may consist of TUBE elements and/or other beam types that have been assigned tubular
sections in the structural analysis.
Joints for post-processing are selected using the JOINt command in BEAMST which specifies the node
numbers at joint positions. All joints are assumed ‘simple’. Elements may be excluded from the check
using the SECOndary command. Yield stresses must be provided for both the chord and brace elements
at a joint.
Joints are automatically classed as K, T, or Y depending on the joint geometry as follows:
1. The chord member is the member with the greatest outside diameter.
2. If two or more potential chord members have equal diameters BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
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API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN)
3. In the case of more than two potential chord members with equal diameters and wall thicknesses, the
first two encountered as shown in the Cross Check Report will be considered.
4. If the CHORd command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
BEAMST selects ‘simple’ joint (brace-chord pair) ‘types’ as follows:
1. Brace members ‘perpendicular’ to the chord members (smaller included angle greater than or equal to
80 degrees) as T joints.
2. Single non-‘perpendicular’ braces are classified as K joints.
3. Cross or Double(DT) joints must be user specified.
4. In the case of user defined K and X joints, no search is performed for a second brace member in the
same brace-chord plane as the first brace.
5. Brace members specified on joint TYPE commands are automatically selected as braces in the above
brace-chord member selection process.
6. No conflict between CHORd command specified members and brace members specified on joint TYPE
commands is allowed.
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHOR commands. Interpolated joint
classifications may be defined using the TYPE command. For K joints a gap dimension appropriate to
the joint may be specified in the TYPE command. A default gap dimension may be specified using the
GAPD command.
If load transfer across chords is to be checked at selected joints, additional chord data must be supplied
using the CHOR EFFE command.
The API LRFD standard utilizes limit state checks with resistance coefficients to achieve the desired level
of safety. In keeping with this principle, applied loads must be multiplied by appropriate factors, as
defined in the code of practice (Section C, Loads), to develop the design load case combinations necessary
for processing. Where non-linear pile analysis is undertaken (using SPLINTER) the design loads must be
applied to the pile model to account for the increased non-linearity this introduces. In situations where
a non-linear pile analysis has not been carried out, the design loads may be produced using the COMB
or CMBV commands utilizing the required load factors. For abnormal loading conditions the ABNO
command may be used to set the resistance coefficients to unity.
Two summary reports are available.
Summary report 1 details the load case producing the highest unity check for each chord/brace pair at
a joint.
Summary report 3 comprises the highest unity check for each selected loadcase for each chord/brace
pair at a joint.
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BEAMST commands applicable to the API LRFD nominal load command are given in Table 5.11: API
LRFD JOIN Commands (p. 294) below and are described in detail in BEAMST Command Reference (p. 51).
An example data file is given in Example 5.8: Example API LRFD JOIN data file (p. 295).
Table 5.11: API LRFD JOIN Commands
Command
Description
Usage
API
LRFD
JOIN
API joint check header command
C
UNIT
Units of length and force
YIEL
Yield stress
GROU
Joint numbers to be reported
ELEM
Joint type and brace element definition
SECT
Chord elements at a joint and associated
parameters
Note
1
C
C
2
C
C
C
3
3
3
SECO
Secondary members to be ignored in checks
DESI
Defines design section properties
GAPD
Define default gap dimension
PROF
Section profiles for use in design
STUB
Tubular member’s end stub dimensions
ABNO
Abnormal loadcases
CASE
Basic loadcases to be reported
COMB
Define a combined loadcase for processing
CMBV
Define a combined loadcase for processing
SELE
Select/redefine a combined/basic loadcase title
SPEC
Basic loadcases from response spectrum analysis
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
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API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN)
Notes
1. See the Command Reference section, specifically the UNIT command.
2. CHORd parameters are compulsory if load transfer across chord checks at cross joints are to be undertaken.
3. At least one CASE, CMBV or COMB command must be included.
Example 5.8: Example API LRFD JOIN data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
UNIT KN M
END
API LRFD ED1 JOIN
*
* Investigate all joints in the model except where
* only one element is connected
*
JOINT ALL
NOT JOINTS 1315 1355 5110 5150
*
* Ignore dummy elements
*
SECONDARY ELEMENTS 801 802
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two wave cases
*
SELE 10 Extreme Wave 1 + Dead Loads + Live Loads
COMB 10 1.35 1 1.1 3 1.1 4
SELE 11 Extreme Wave 2 + Dead Loads + Live Loads
COMB 11 1.35 2 1.1 3 1.1 4
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Specify the chord elements for one of the joints
*
CHORD 1130 122 123
*
* Request cross chord check for one X joint
*
TYPE.OF.JOINT X
CHORD EFFE
*
* Set some joints as being Y
*
TYPE.OF.JOINT 1130 Y 102
TYPE.OF.JOINT 1130 Y 103
*
* Ask explicitly for all reports
*
PRIN XCHK UNCK SUNI N MM SUM3 SUM1
END
STOP
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5.8.2. API LRFD JOIN Check Report
The detailed nominal load unity check report provides information on joint geometric parameters, joint
type, acting chord and brace loading, Qf and Qu factors, nominal load allowables and unity checks for
each joint/brace requested. This may be selected using the PRINt UNCK command. When an interpolatory
joint type classification is being employed, two sets of nominal load allowables are reported, one for
each joint classification type, and these pertain to joints classified as 100% of the respective joint types.
The final column is reserved for messages. These may be summarized as follows:
FAIL
Joint/brace pair has a utilization exceeding unity or fails parameter checks (flagged with BETA, NOCK,
NOCY or NOJN).
PNT9
Unity check value exceeds 0.9.
NOCY
Chord yield stress zero or negative, no checks possible.
NOJN
No joint strength check possible. Brace or chord yield value zero or negative.
NOCK
No chord brace pairs to check, β greater than unity or θ < 200.
BETA
β > 0.9 so load transfer across chord check is invalid.
THET
Brace angle, θ, < 200 so no check is possible.
XCHK
Joint has been defined as an X or DT, but chord effective length and nominal thickness data has not
been supplied and load transfer across chord check has not been undertaken.
5.8.3. API LRFD JOIN Nomenclature
API LRFD JOIN uses the following nomenclature:
5.8.3.1. API LRFD JOIN Nomenclature - Dimensional
5.8.3.2. API LRFD JOIN Nomenclature - Acting Forces and Stresses
5.8.3.3. API LRFD JOIN Nomenclature - Allowable Stresses and Unity Checks
5.8.3.4. API LRFD JOIN Nomenclature - Parameters
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API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN)
5.8.3.1. API LRFD JOIN Nomenclature - Dimensional
Lc
Effective chord length (Figure E.3-6 of API Code)
D
Chord outside diameter
d
Brace outside diameter
R
Chord radius
r
Brace radius
T
Chord thickness
Tn
Nominal chord thickness (away from the joint)
t
Brace thickness
γ
Ratio between the chord radius and thickness R/T
τ
Ratio between the thickness of the brace and chord t/T
θ
Angle between brace and chord
β
Ratio between the diameter of the brace and chord d/D
g
K joint gap
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5.8.3.2. API LRFD JOIN Nomenclature - Acting Forces and Stresses
P
Brace axial force
Mip
Brace in-plane bending moment
Mop
Brace out-of-plane bending moment
faxc
Chord axial stress component
fipc
Chord in-plane bending stress
fopc
Chord out-of-plane bending stress
faxb
Brace axial stress component
fipb
Brace in-plane bending stress
fopb
Brace out-of-plane bending stress
fb
Resultant brace bending stress
5.8.3.3. API LRFD JOIN Nomenclature - Allowable Stresses and Unity Checks
fyb
Brace yield stress
fy
Chord yield stress
Pa
Allowable axial force
Px
Allowable axial force for load transfer across chords
Maip
Allowable in-plane bending moment
Maop
Allowable out-of-plane bending moment
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API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN)
UCax
Axial force unity check
UCip
In-plane bending unity check
UCop
Out-of-plane bending unity check
UCx
Load transfer across chord unity check
UCco
Combined axial and bending unity check
UCjy
Joint strength unity check
5.8.3.4. API LRFD JOIN Nomenclature - Parameters
φq
Yield stress resistance factor
φj
Connection resistance factor
5.8.4. API Allowable Nominal Loads and Unity Checks
This section discusses the following topics:
5.8.4.1. API LRFD JOIN - Chord Design Factor Qf
5.8.4.2. API LRFD JOIN - Ultimate Strength Factor Qu
5.8.4.3. API LRFD JOIN - Allowable Nominal Loads
5.8.4.4. API LRFD JOIN - Load Transfer Across Chords
5.8.4.5. API LRFD JOIN - Nominal Load Unity Checks
5.8.4.6. API LRFD JOIN - Combined Axial and Bending Unity Checks UCco
5.8.4.7. API LRFD JOIN - Interpolated Joints
5.8.4.8. API LRFD JOIN - Load Transfer Check UCx
5.8.4.9. API LRFD JOIN - Joint Strength Unity Check UCjy
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5.8.4.1. API LRFD JOIN - Chord Design Factor Qf
Clause/(Eqn)
Commentary
Message
5.8.4.2. API LRFD JOIN - Ultimate Strength Factor Qu
Clause/(Eqn)
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Commentary
Message
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API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN)
5.8.4.3. API LRFD JOIN - Allowable Nominal Loads
Clause/(Eqn)
Commentary
Message
5.8.4.4. API LRFD JOIN - Load Transfer Across Chords
Clause/(Eqn)
Commentary
Message
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5.8.4.5. API LRFD JOIN - Nominal Load Unity Checks
Clause/(Eqn)
Commentary
Message
5.8.4.6. API LRFD JOIN - Combined Axial and Bending Unity Checks UCco
Clause/(Eqn)
Commentary
Message
5.8.4.7. API LRFD JOIN - Interpolated Joints
Clause/(Eqn)
Commentary
Message
If an interpolatory joint type classification is specified,
two sets of geometry and loading factors Qu are calculated (Qu1 and Qu2). Two corresponding sets of nominal
load allowables are then computed where each assumes
the joint to be 100% of the respective types. If the joint
is specified as C% joint type 1, the axial unit check is
calculated as:
with UCip and UCop being calculated in a similar manner.
The combined unity checks are calculated as before using
the interpolated unity check values corresponding to
each component of stress.
5.8.4.8. API LRFD JOIN - Load Transfer Check UCx
Clause/(Eqn)
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Commentary
Message
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API Load and Resistance Factor Design Nominal Load Check (API LRFD JOIN)
5.8.4.9. API LRFD JOIN - Joint Strength Unity Check UCjy
Clause/(Eqn)
Commentary
Message
5.8.5. Spectral Expansion for Joint Checks (API LRFD)
In response spectrum analysis using modal superposition (Ref. 12) structure displacements and forces
calculated represent estimated maxima. Such estimated maxima are, in general, unsigned (positive).
For the purpose of checking joints to API, a series of worst static-spectral possible loadcases must be
generated from the member unsigned spectral and signed static end forces.
The signs applied to the spectral end forces when generating a series of worst cases depends upon the
unity check being considered and details of the signs adopted/deduced are given in this section.
In BEAMST it is assumed that unity checks can be performed by considering the combination of static
and dynamic conditions to be purely a static condition. Any joint type identification dependant on
axial load is carried out prior to any combinations with dynamic cases.
There are eight possible unique combinations of signs, or ‘spectral expansions’, which can be applied
to unsigned spectral axial and local bending stresses:
2 - axial (tension and compression)
x
2 - local Y bending (hog and sag)
x
2 - local Z bending (hog and sag)
and each is denoted by a single alphabetic letter code in BEAMST in the range R-Y as shown in Figure 5.2: Automatic Signed Spectral Expansion Codes for Joint checks and the Respective Signs Applied
to Chord/Brace Unsigned Spectral Constituents (p. 263). The spectral expansion codes indicating the
signs chosen by BEAMST for both the chord and brace member spectral stresses are appended to the
loadcase number in the unity check report, the code for the chord member being appended first.
In general the influence of both the chord and brace members’ acting stress is such that by maximizing
the total acting chord and brace stresses the resulting unity check values are also maximized. In such
cases BEAMST adopts the chord and brace member spectral axial and local bending stresses of the
same sign as the static axial and local bending static stresses respectively. There are two conditions in
which the above does not hold and these may be summarized as follows:
• If all the extreme fiber stresses in the chord are in tension Qf defaults to unity. To check if compression
produces a more onerous condition the sign of the axial stress is reversed and Qf recomputed if overall
compression is achieved.
• If a cross joint is specified two values of the axial component of Qu may be calculated depending on
whether the axial stress in the brace is compressive or tensile. If a large spectral axial stress is to be combined with a small static stress it is not obvious which spectral expansion leads to the worst unity check
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BEAMST API Theory
value. BEAMST considers both possibilities and adopts a spectral expansion which leads to the worst unity
check.
Figure 5.3: Automatic Signed Spectral Expansion Codes for Joint Checks and the Respective Signs
Applied to Chord/Brace Unsigned Spectral Constituents
Notes
Spectral expansion Z represents the trivial case of static components only in a static-spectral loadcase.
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Chapter 6: BEAMST BS59 Theory
The BEAMST commands applicable to BS59 command data are given in Table 6.1: BS59 MEMB Commands (p. 306) and described in detail in BEAMST Command Reference (p. 51). An example data file is
given in Example 6.1: Example of a BS59 MEMB data file (p. 307).
6.1. BS5950 Allowable Member Check (BS59 MEMB)
This section discusses the following topics:
6.1.1. BS59 MEMB Overview
6.1.2. BS59 Allowable Unity Check Report
6.1.3. BS59 MEMB Nomenclature
6.1.4. BS5950 Local Cross Section Checks
6.1.5. BS5950 Overall Member Checks
6.1.6. BS59 MEMB - Thin or Slender Webs
6.1.1. BS59 MEMB Overview
Two types of stress check are carried out:
1. Local cross-section checks, which are performed at both element ends, at each change of section for
stepped beams and at each section defined by the user with the SECT command.
2. Overall buckling checks which are carried out once for each requested element.
Element selection may be done on a group or element number basis using the GROU and ELEM commands respectively.
Loadcases from the preceding structural analysis may be selected for processing using either the CASE
command or COMB and CMBV commands if combinations are required. Acting and ultimate
stresses/forces are calculated and design checks are performed at element ends, at each change of
section for stepped beams and at each user requested section position defined by the SECT or SEAR
commands. If the SEAR command is used, the additional section forces and stresses and resulting unity
checks are not reported unless the respective maxima are found to exist at such sections.
Various member and section properties may be defined using the DESI, PROF, YIEL, EFFE, UNBR and
ULCF commands. The units of all input data must be defined using the UNIT command (unless ASAS
units are operational).
Output reports are requested using the PRIN command. One set of output reports is printed for each
element. Member property, force and stress reports are requested using the PROP, FORC and STRE
subcommands respectively. The unity check report is requested with the UNCK subcommand. Forces
are reported in the local section and global buckling checks and output units may be specified using
the FUNI subcommand.
Four summary report files are available with the BS5950 code check:
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Summary report 1 is requested with the PRIN SUM1 command and comprises the highest yield and
buckle combined stress unity checks and their components for each selected element over all loadcases
selected.
Summary report 3 is requested with the PRIN SUM3 command and comprises the highest unity check
for each selected loadcase for each element selected.
Summary report 4 is requested with the PRIN SUM4 command and provides the three worst unity checks
for each selected group, together with the distribution of unity check values. The distribution provides
information on the number of unity checks exceeding an upper limit (default 1.0), less than a lower
limit (default 0.5), and the number in the midrange.
Summary report 5 is requested with the PRIN SUM5 command and provides information about the
highest member forces and moments for each selected group. For each force type the worst four values
are reported, together with the element number, loadcase and position along the element.
The BEAMST commands applicable to BS59 command data are given in Table 6.1: BS59 MEMB Commands (p. 306) below and described in detail in BEAMST Command Reference (p. 51). An example data
file is given in Example 6.1: Example of a BS59 MEMB data file (p. 307).
Table 6.1: BS59 MEMB Commands
Command
Description
Usage
BS59
MEMB
BS59 member check header command
C
UNIT
Units of length and force
C
1
YIEL
Yield stress
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SEAR
Search other sections in addition to those requested on the
SECT command for maximum forces and stresses
SIMP
Select elements for simple checks
MFAC
Define moment reduction factors for overall buckling check
MLTF
Define L.T.B. moment reduction factor for overall buckling
check
DESI
Defines design section properties
C
3
PROF
Section profiles for use in design
EFFE
Effective lengths/factor
UNBR
Unbraced lengths of element
ULCF
Unbraced length of compression flange
CASE
Basic loadcases to be reported
C
4
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Note
BS5950 Allowable Member Check (BS59 MEMB)
Command
Description
Usage
Note
COMB
Define a combined loadcase for processing
C
4
CMBV
Define a combined loadcase for processing
C
4
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. Compulsory for non-tubulars unless Sections have been used for all non-tubular elements to be processed
in the preceding analyses.
4. At least one CASE, CMBV or COMB command must be included.
Example 6.1: Example of a BS59 MEMB data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE DECA
OPTION GOON END
BS5950 MEMB
*
* Select all elements using the GROUP command except
* elements 991 and 992 - dummy elements
*
GROUP ALL
NOT ELEMENT 991 992
UNIT KN M
*
* Define section properties for some elements that
* used areas and inertia values in the ASAS run
*UNITS MM
DESI RHS 900.0 400.0 40.0 ELEMENT 851 TO 854 861
: 931 TO 942
UNITS M
*
* Examine two load cases including jacket loading
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Indicate that these loadcases are extreme events
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*
EXTR 10 11
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main deck beams use effective length
* coefficient of 1.0
* Deck columns use effective length coeff of 1.2
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFE 0.8 ELEM 851 To 854
EFFE 1.0 GROU ALL
*
* Unbraced lengths need redefining
* assumes no lateral restraint from deck plating
*
UNBR FACT 1.0 2.0 ELEM 701 704
UNBR FACT 2.0 1.0 ELEM 706 707
UNBR FACT 2.0 ELEM 702 703
UNBR LENG 4.875 19.5 ELEM 711 713
UNBR LENG 9.75 19.5 ELEM 712
*
* Override program computed moment amplification RF
*
MFAC 1.0 0.85 ELEM 711 712 713
MFAC 1.0 0.85 ELEM 701 TO 704
MFAC 0.85 1.0 ELEM 702 703
MFAC 0.85 1.0 ELEM 706 707
*
* Check mid-span and quarter point sections
*
SECT 0.25 0.5 0.75 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 SUM3 SUM4
END
STOP
6.1.2. BS59 Allowable Unity Check Report
The unity check report is presented on an element by element basis, with separate tables reporting the
local cross-section unity check and overall buckle unity check results. For each tube the header line
displays the element number, the associated node numbers, the element group and the units in use.
For the local cross-section unity check report, results are printed for each of the selected positions (or
sections) along the element for each loadcase in turn.
For the overall buckling check a single set of results are reported for the whole element. For this report,
the letter C after the loadcase number indicates a compressive axial force, T indicates a tensile force.
The final column of each report is reserved for messages. These may be summarized as follows:
FAIL
Code check failure for this member.
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
308
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BS5950 Allowable Member Check (BS59 MEMB)
TENS
Section classified as plastic due to tensile load (α < 0, Table 7)
MCFO
Moment capacities calculated for flanges only
SLMN
Minor axis slenderness exceeds 180
SLMJ
Major axis slenderness exceeds 180
SIMP
Simplified checks (Clauses 4.8.2 and 4.8.3.2)
APPH
Thin web Appendix H in the BS5950 code of practice used for moment capacity.
6.1.3. BS59 MEMB Nomenclature
BS59 MEMB uses the following nomenclature:
6.1.3.1. BS59 MEMB Nomenclature - Dimensional
6.1.3.2. BS59 MEMB Nomenclature - Acting Forces and Stresses
6.1.3.3. BS59 MEMB Nomenclature - Allowable Stresses and Unity Checks
6.1.3.1. BS59 MEMB Nomenclature - Dimensional
(a) Rolled Sections
(b) Welded Sections
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BEAMST BS59 Theory
A
Cross-sectional area
Aw
Web area
ZJ
Elastic modulus (major axis)
ZN
Elastic modulus (minor axis)
SJ
Plastic modulus (major axis)
SN
Plastic modulus (minor axis)
IJ
Moment of inertia (major axis)
IN
Moment of inertia (minor axis)
AJ
Shear area (major axis)
AN
Shear area (minor axis)
LUNBY
Unbraced member lengths in the local y axis
LUNBZ
Unbraced member lengths in the local z axis
LULCF
Unbraced length of the member compression flange
ZFJ
Elastic modulus (major axis) ignoring webs
SFJ - Plastic modulus (major axis) ignoring webs
ZFN - Elastic modulus (minor axis) ignoring webs
310
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BS5950 Allowable Member Check (BS59 MEMB)
SFN - Plastic modulus (minor axis) ignoring webs
6.1.3.2. BS59 MEMB Nomenclature - Acting Forces and Stresses
P
Axial load (+ve tension)
MT
Torsional moment
MMJ
Major axis moment
MMN
Minor axis moment
SMJ
Major axis shear force
SMN
Minor axis shear force
6.1.3.3. BS59 MEMB Nomenclature - Allowable Stresses and Unity Checks
MCJ
Major axis bending capacity
MCN
Minor axis bending capacity
Mb
Lateral torsional buckling capacity
PCJ
Axial buckling capacity for major axis
PCN
Axial buckling capacity for minor axis
UCAX
Unity check - axial tension
UCMJ
Unity check - major axis bending
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BEAMST BS59 Theory
UCMN
Unity check - minor axis bending
UCSJ
Unity check - major axis shear
UCSN
Unity check - minor axis shear
UCXM
Unity check - axial + moment
UCBJ
Unity check - major axis buckling
UCBN
Unity check - minor axis buckling
UCLT
Unity check - lateral torsional
UCCM
Unity check - compression + moment
py
Design strength
YRF
Yield reduction factor for compression flange
YRW
Yield reduction factor for the web
YRT
Yield reduction factor for tube
E
Young’s modulus
Notes
Plastic section modulus values are recalculated by BEAMST rather than passed through from ASAS. All
BEAMST plastic modulus calculations ignore the effects of fillet radii. This is necessary to ensure the
validity of some equations used in the calculation of section capacities.
6.1.4. BS5950 Local Cross Section Checks
Clause/(Eqn)
312
Local Cross Section Check
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Local Cross Section Check
Message
Six local cross-section checks are carried out; the
checks carried out and the headings under which they
are reported in the BEAMST output file are as follows:
4.6.1
4.2.3
4.2.3
4.2.5/4.2.6
4.2.5/4.2.6
4.2.6
4.8.24.8.3.2
1. AXIAL
axial tension
2. SHR(MJ.AX)
major axis shear
3. SHR(MN.AX)
minor axis shear
4. BND(MJ.AX)
major axis bending
5. BND(MN.AX)
minor axis bending
6. AX+MOM
axial force + moment
6.1.4.1. BS59 MEMB - Section Classification
Clause/(Eqn)
Section Classification
Message
The classification of I and RHS sections is dependent
on the slenderness of the compression flange and the
web. The overall classification of the section being the
more critical of the compression flange and web classifications.
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BEAMST BS59 Theory
Clause/(Eqn)
314
Section Classification
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Section Classification
Message
If α > 2
If 0 < α < 2
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BEAMST BS59 Theory
Clause/(Eqn)
Section Classification
Message
If α < 0
TWEB
then the plastic neutral axis is in the compression
flange and the section is assumed as having tension
throughout. The section is then classified as plastic.
316
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Section Classification
Message
Thin Web
6.1.4.2. BS59 MEMB - Axial Tension Unity Check
Clause/(Eqn)
Axial Tension Unity Check
Message
6.1.4.3. BS59 MEMB - Major Axis Shear Unity Check
Clause/(Eqn)
Major Axis Shear Unity Check
Message
6.1.4.4. BS59 MEMB - Minor Axis Shear Unity Check
Clause/(Eqn)
Minor Axis Shear Unity Check
Message
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317
BEAMST BS59 Theory
Clause/(Eqn)
Minor Axis Shear Unity Check
Message
6.1.4.5. BS59 MEMB - Major Axis Shear Unity Checks, Low Shear Load
Clause/(Eqn)
Low Shear Load
Message
For cases where SMJ < 0.6*(0.6AJ)py, where AJ is as
defined in BS59 MEMB - Major Axis Shear Unity
Check (p. 317), the major axis bending capacity MCJ is
calculated as follows:
318
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Low Shear Load
Message
6.1.4.6. BS59 MEMB - Major Axis Shear Unity Checks, High Shear Load
Clause/(Eqn)
High Shear Load
Message
For cases where SMJ > 0.6*(0.6AJ)py, where AJ is as
defined in BS59 MEMB - Major Axis Shear Unity
Check (p. 317), the major axis bending capacity MCJ is
calculated as follows:
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319
BEAMST BS59 Theory
Clause/(Eqn)
320
High Shear Load
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
High Shear Load
Message
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321
BEAMST BS59 Theory
Clause/(Eqn)
322
High Shear Load
Message
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BS5950 Allowable Member Check (BS59 MEMB)
6.1.4.7. BS59 MEMB - Minor Axis Shear Unity Checks, Low Shear Load
Clause/(Eqn)
Low Shear Load
Message
For cases where SMN < 0.6*(0.6AJ)py, where AJ is as
defined in BS59 MEMB - Minor Axis Shear Unity
Check (p. 317), the major axis bending capacity MCN is
calculated as follows:
For cases where SMJ < 0.6*(0.6AJ)py, where AJ is as
defined in BS59 MEMB - Major Axis Shear Unity
Check (p. 317), the major axis bending capacity MCJ is
calculated as follows:
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BEAMST BS59 Theory
Clause/(Eqn)
Low Shear Load
Message
6.1.4.8. BS59 MEMB - Minor Axis Shear Unity Checks, High Shear Load
Clause/(Eqn)
High Shear Load
Message
For cases where SMN > 0.6*(0.6AJ)py, where AJ is as
defined in BS59 MEMB - Minor Axis Shear Unity
Check (p. 317), the minor axis bending capacity MCN is
calculated as follows:
324
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
High Shear Load
Message
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325
BEAMST BS59 Theory
Clause/(Eqn)
326
High Shear Load
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
High Shear Load
Message
6.1.4.9. BS59 MEMB - Axial Force plus Moment Unity Check
Clause/(Eqn)
Axial Force plus Moment Unity Check
Message
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327
BEAMST BS59 Theory
Clause/(Eqn)
328
Axial Force plus Moment Unity Check
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Axial Force plus Moment Unity Check
Message
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329
BEAMST BS59 Theory
Clause/(Eqn)
330
Axial Force plus Moment Unity Check
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Axial Force plus Moment Unity Check
Message
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331
BEAMST BS59 Theory
Clause/(Eqn)
332
Axial Force plus Moment Unity Check
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Axial Force plus Moment Unity Check
Message
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BEAMST BS59 Theory
Clause/(Eqn)
Axial Force plus Moment Unity Check
Message
6.1.4.10. BS59 MEMB - Simplified Axial Force and Moment
Clause/(Eqn)
Simplified Axial Force and Moment
Message
If the simplified local capacity check for plastic or
compact cross-sections is adopted using the SIMP
command, the following checks are undertaken:
334
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Simplified Axial Force and Moment
Message
6.1.5. BS5950 Overall Member Checks
Clause/(Eqn)
Overall Member Check
Message
6.1.5.1. BS59 MEMB - Major Axis Compressive Buckling
Clause/(Eqn)
Major Axis Compressive Buckling
Message
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335
BEAMST BS59 Theory
Clause/(Eqn)
336
Major Axis Compressive Buckling
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Major Axis Compressive Buckling
Message
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BEAMST BS59 Theory
6.1.5.2. BS59 MEMB - Minor Axis Compressive Buckling
Clause/(Eqn)
338
Minor Axis Compressive Buckling
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Minor Axis Compressive Buckling
Message
6.1.5.3. BS59 MEMB - Lateral Torsional Buckling
Clause/(Eqn)
Lateral Torsional Buckling
Message
The lateral torsional buckling behavior of an I-section
is governed by the flanges, hence it has been assumed
that the reduced design strength should take account
only of the flange stress reduction factors.
Hence pyR = pyYRF
All lateral torsional buckling calculations are based on
the maximum major axis bending moment at any point
along the member (MMJ).
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BEAMST BS59 Theory
Clause/(Eqn)
340
Lateral Torsional Buckling
Message
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Lateral Torsional Buckling
Message
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BEAMST BS59 Theory
Clause/(Eqn)
Lateral Torsional Buckling
Message
Tubular sections are not checked for lateral torsional
buckling. Note, however, that the buckling resistance
moment, Mb, is computed for subsequent use if the
simplified method has been selected.
342
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Lateral Torsional Buckling
Message
Mb = pySJ
6.1.5.4. BS59 MEMB - Overall Buckling
Clause/(Eqn)
Overall Buckling
Message
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BEAMST BS59 Theory
6.1.5.5. BS59 MEMB - Overall Buckling - Simplified Method
Clause/(Eqn)
Overall Buckling - Simplified Method
Message
6.1.6. BS59 MEMB - Thin or Slender Webs
Clause/(Eqn)
Thin or Slender Webs
H.3
When d/t > 63e the web is classified as slender.
Message
For slender webs, a moment capacity of the web is
computed by adopting the interaction formula given
in Appendix H3.2 in the BS5950 code of practice. For
a given applied shear, a proportion of the applied
longitudinal loading is calculated which satisfies the
interaction formula. The derivation of this proportion
of loading is as follows:
344
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BS5950 Allowable Member Check (BS59 MEMB)
Clause/(Eqn)
Thin or Slender Webs
Message
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BEAMST BS59 Theory
Clause/(Eqn)
Thin or Slender Webs
Message
For computing the moment capacity in the absence
of axial load, fc is set to zero and the above equation
solved directly.
Mflng is the reduced moment capacity of the flanges
alone when subjected to an axial stress of (1-α)fc.
346
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Chapter 7: BEAMST DS44 Theory
The DS449 header command in BEAMST is used to request strength checks to the Danish Standards
DS449 (Ref. 9) and DS412 (Ref. 10) for tubular members.
The DS449 and DS412 standards specify ultimate limit state checks and the partial coefficient method
is used. In keeping with this principle, applied loads must be multiplied by appropriate factors, as
defined in the code of practice (DS449, Section 5, Safety), to develop the design load case combinations
necessary for processing. Where non-linear pile analysis is undertaken (using SPLINTER) the design loads
must be applied to the pile model to account for the increased non-linearity this introduces. In situations
where a non-linear pile analysis has not been carried out, the design loads may be produced using the
COMB or CMBV commands utilizing the required load factors. Partial material coefficients are specified
on the basis of a number of safety classes and in BEAMST either a normal or high safety class may be
selected, high being the default.
Two types of check are available, member checks and joint checks, and these are requested using the
MEMB and JOIN subcommands respectively.
7.1. DS449 Member Checks (DS44 MEMB)
This section discusses the following topics:
7.1.1. DS44 MEMB Overview
7.1.2. DS449 MEMB Unity Check Report
7.1.3. DS449 MEMB Nomenclature
7.1.4. DS449 Member Unity Check Calculations
7.1.1. DS44 MEMB Overview
The DS44 MEMB header command in BEAMST is used to request that ultimate limit state checks, consisting of von Mises yield, total buckling and local buckling checks, be performed to DS449 and DS412
for tubular members. Elements may be classified as type ao, a, b, c or d for use in the column buckling
curves of DS412.
Elements may be selected on an element or group basis using the ELEM or GROU commands respectively.
Loadcases from the preceding structural analysis may be selected for processing using either the CASE
command (if the loads have already been factored and combined) or the COMB and CMBV commands
(which permit combinations and factoring to be undertaken within BEAMST).
Acting and critical stresses are calculated and design checks are carried out at the element ends, at
changes of section for stepped beams and at each user requested section defined by the SECT or SEAR
commands. If the SEAR command is used, the additional section forces and stresses and resulting unity
checks are not reported unless the respective maxima are found to exist at such sections.
Output reports are requested with the PRIN command. Two unity check reports are printed if the UNCK
subcommand is present. The first gives critical stresses and unity check values for von Mises yielding
and local buckling at each section position. If the WAVE, ELEV, MOVE and GRAV commands are present
in the data, this report is automatically extended to include local buckling checks for hydrostatic overRelease 15.0 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information
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347
BEAMST DS44 Theory
pressure. The second report gives critical stresses and unity check values for total buckling of the
member. Element property, force and stress reports are printed if the subcommands PROP, FORC, and
STRE respectively are present in the PRIN command. Three summary reports may be printed:
Summary report 1 is requested with the PRIN SUM1 command and gives the highest unity check values
for each element.
Summary report 3 is requested with the PRIN SUM3 command and consists of the highest unity check
for each selected loadcase for each element selected.
Summary report 4 is requested with the PRIN SUM4 command and provides the three worst unity checks
for each selected group, together with the distribution of unity check values. The distribution provides
information on the number of unity checks exceeding an upper limit (default 1.0), less than a lower
limit (default 0.5), and the number in the mid-range.
The total buckling check of DS412 requires the evaluation of equivalent moments based on the values
of the end moments and the maximum free bending moment. In order that the maximum free bending
moment is estimated properly it is necessary to specify at least one section along the beam, preferably
at the mid. The free bending moment values are reported at each section in the element force report.
The BEAMST commands applicable to the DS44 MEMB command are in Table 7.1: DS449 MEMB Commands (p. 348) and are described in detail in BEAMST Command Reference (p. 51). An example data file
is given in Example 7.1: Example of a DS44 MEMB data file (p. 349).
Table 7.1: DS449 MEMB Commands
Command
Description
Usage
DS449
MEMB
DS449 member check header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
MCOF
ELEV
Water depth and density
MOVE
Water axis origin in global structure axis system
WAVE
Wave height and period
GRAV
Gravitational accelerations relative to structure axis system
GROU
Groups to be reported
C
3
ELEM
Elements to be reported
C
3
SECT
Sections to be reported
SEAR
Additional sections to be reported automatically
DESI
Defines design section properties
PROF
Section profiles for use in design
348
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C
2
C
2
4
DS449 Member Checks (DS44 MEMB)
Command
Description
Usage
Note
EFFE
Effective lengths/factors
ULCF
Length of tubular between stiffening rings, diaphragms, etc.
UNBR
Unbraced lengths of element
CASE
Basic loadcases to be reported
C
5
COMB
Define a combined loadcase for processing
C
5
CMBV
Define a combined loadcase for processing
C
5
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. Compulsory only if hydrostatic pressure effects to be examined.
3. At least one GROUP or ELEM command must be included.
4. Not compulsory because DS449 only checks tubular members.
5. At least one CASE, CMBV or COMB command must be included.
Example 7.1: Example of a DS44 MEMB data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
DS449 MEMB HIGH C
*
* Horizontal plan bracing level -50 m
*
GROUP 1
UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine four load combinations
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349
BEAMST DS44 Theory
*
SELE 10 Extreme Wave + Dead Loads + Topside Loads
COMB 10 0.75 1 1.0 3 1.3 4
SELE 11 Extreme Wave + Dead Loads + Topside Loads
COMB 11 1.3 1 1.0 3 1.0 4
SELE 12 Extreme Wave + Dead Loads + Topside Loads
COMB 12 1.0 1 1.0 3 1.0 4
SELE 13 Extreme Wave + Dead Loads + Topside Loads
COMB 13 0.75 1 1.0 3 1.0 4
*
* Include hydrostatic checks
*
ELEVATION 0.0 -50.0 1.025
GRAVITY 0.0 0.0 -9.81
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main plan bracing members use effective length
* coefficient of 0.8
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFECTIVE.LENGTH 0.8 ELEMENTS 105 106
EFFECTIVE.LENGTH 0.8 ELEMENTS 101 TO 104
EFFECTIVE.LENGTH 0.8 ELEMENTS 107 TO 110
EFFECTIVE.LENGTH 1.0 GROUP 1
*
* Out of plane unbraced lengths need redefining
*
UNBRACED FACT 2.0 1.0 ELEM 105 106
UNBRACED LENG 15.0 7.5 ELEM 102 103
*
* Check mid-span sections
*
SECT 0.5 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC STRE SUNI N MM SUM1 SUM3
END
STOP
(action comb a)
(action comb b)
(action comb c)
(action comb d)
SUM4
7.1.2. DS449 MEMB Unity Check Report
The final column of each report is reserved for messages. These may be summarized as follows:
FAIL
Code check failure for this member.
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
SLRF
Member slenderness ratio exceeds 200
RELS
Relative slenderness ratio exceeds unity for the local buckling code check
350
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DS449 Member Checks (DS44 MEMB)
CONS
The distance between restraints (unbraced length) is less than the value specified in D.1.2.3 (Ref. 9) for
hydrostatic overpressure and could lead to overdimensioning of the section
NOHC
No hydrostatic check was possible because the parameter limits for the k2 coefficient were exceeded
Buckling checks are not performed when members are in tension. When the axial force is tensile the
message ‘MEMBER IS IN TENSION‘ appears in the total buckle unity check report. When the extreme
fiber stress is tensile a ‘+’ is placed after any critical stress or unity check value in which buckling is not
considered.
7.1.3. DS449 MEMB Nomenclature
DS449 MEMB uses the following nomenclature:
7.1.3.1. DS449 MEMB Nomenclature - Dimensional
7.1.3.2. DS449 MEMB Nomenclature - Acting Forces and Stresses
7.1.3.3. DS449 MEMB Nomenclature - Allowable Stresses and Unity Checks
7.1.3.1. DS449 MEMB Nomenclature - Dimensional
A
Cross-sectional area
R
Mean radius of tube
t
Thickness
k
Core radius
k'
Effective length factor
L
Unbraced length of member
r
Radius of gyration
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S
Section modulus
7.1.3.2. DS449 MEMB Nomenclature - Acting Forces and Stresses
N
Axial force
Nely, Nelz
Euler force in y or z direction
My, Mz
Bending moment about y or z axis
fa
Axial stress
fb
Resultant bending stress
fh
Hoop stress
fv
Maximum shear stress
fvm
von Mises stress
Mo
Maximum free bending moment from all sections examined along member
7.1.3.3. DS449 MEMB Nomenclature - Allowable Stresses and Unity Checks
fCRa
Critical compressive design stress for axial force and bending moment
fCRh
Critical hoop stress
fCRc
Critical combined stress
fy
Yield stress
E
Young’s modulus
ν
Poisson’s ratio
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DS449 Member Checks (DS44 MEMB)
UCvm
von Mises yield check
UCs
Shear stress unity check
UCa
Local buckling under axial and bending stress
UChh
Local buckling due to hydrostatic overpressure
UCc
Combined axial, moment and hydrostatic pressure
UC1, UC2
Total buckle checks
7.1.4. DS449 Member Unity Check Calculations
This section discusses the following topics:
7.1.4.1. DS449 MEMB - Partial Material Coefficients
7.1.4.2. DS449 MEMB - von Mises Stress
7.1.4.3. DS449 MEMB - Total Buckling
7.1.4.4. DS449 MEMB - Local Buckling Axial and Bending Stresses
7.1.4.5. DS449 MEMB - Local Buckling Hydrostatic Overpressure
7.1.4.6. DS449 MEMB - Local Buckling Combined Actions
7.1.4.7. DS449 MEMB - Unity Check Values
7.1.4.1. DS449 MEMB - Partial Material Coefficients
Clause/(Eqn)
Partial Material Coefficients
Message
7.1.4.2. DS449 MEMB - von Mises Stress
Clause/(Eqn)
von Mises Stress
Message
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BEAMST DS44 Theory
Clause/(Eqn)
von Mises Stress
Message
7.1.4.3. DS449 MEMB - Total Buckling
Clause/(Eqn)
354
Total Buckling
Message
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DS449 Member Checks (DS44 MEMB)
Clause/(Eqn)
Total Buckling
Message
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BEAMST DS44 Theory
Clause/(Eqn)
Total Buckling
Message
7.1.4.4. DS449 MEMB - Local Buckling Axial and Bending Stresses
Clause/(Eqn)
Local Buckling Axial and Bending Stresses
Message
The following quantities are obtained at each user
defined section and change of section along the beam.
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DS449 Member Checks (DS44 MEMB)
Clause/(Eqn)
Local Buckling Axial and Bending Stresses
Message
7.1.4.5. DS449 MEMB - Local Buckling Hydrostatic Overpressure
Clause/(Eqn)
Local Buckling Hydrostatic Overpressure
Message
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BEAMST DS44 Theory
Clause/(Eqn)
358
Local Buckling Hydrostatic Overpressure
Message
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DS449 Member Checks (DS44 MEMB)
7.1.4.6. DS449 MEMB - Local Buckling Combined Actions
Clause/(Eqn)
Local Buckling Combined Actions
Message
7.1.4.7. DS449 MEMB - Unity Check Values
Clause/(Eqn)
Unity Check Values
Message
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Clause/(Eqn)
Unity Check Values
Message
7.2. DS449 Joint Checks (DS44 JOIN)
This section discusses the following topics:
7.2.1. DS44 JOIN Overview
7.2.2. NPD JOIN Unity Check Report
7.2.3. DS449 JOIN Nomenclature
7.2.4. DS449 Joint Checks
7.2.1. DS44 JOIN Overview
The JOIN subcommand requests joint checks to DS449. These checks are similar to the API 15th edition
nominal load checks. Joints for processing are selected using the JOIN command and all joints are assumed to be simple and non-overlapping.
Elements may be excluded from selection as chords or braces using the SECOndary command. Joints
are automatically classed as K, T or Y depending on the joint geometry as follows.
1. The chord member is the member with the greatest outside diameter.
2. If two or more potential chord members have equal diameters, BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
3. In the case of two or more potential chord members with equal diameters and wall thicknesses, the first
two encountered as shown in the Cross Check Report will be considered.
4. If the CHORd command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
BEAMST selects ‘simple’ joint (brace-chord pair) ‘types’ as follows:
1. Brace members ‘perpendicular’ to the chord members (smaller included angle greater than or equal to
80 degrees) as T joints.
2. Single non-‘perpendicular’ braces are classified as Y joints. Two non-‘perpendicular’ braces on the same
side of the chord are classified as K joints.
3. Cross or Double(DT) joints must be user specified.
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DS449 Joint Checks (DS44 JOIN)
4. In the case of user defined K and X joints, no search is performed for a second brace member in the
same brace-chord plane as the first brace.
5. Brace members specified on joint TYPE commands are automatically selected as braces in the above
brace-chord member selection process.
6. No conflict between CHORd command specified members and brace members specified on joint TYPE
commands is allowed.
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHOR commands. Interpolated joint
classifications may be defined using the TYPE command. For K joints DS449 requires the evaluation of
the mean of the two brace diameters. To allow BEAMST to do this a second brace may be defined in
the TYPE command.
A detailed unity check report is requested using the PRIN UNCK command. This gives details of joint
geometry and type, the acting and ultimate brace loads, and the parameters C and µ. For interpolated
joint classifications ultimate loads are printed for each joint type, assuming the joint to be 100% of the
relevant type in each case. Five unity check values are printed and the maximum is flagged for ease of
reference.
Summary report 3 comprises the highest unity check for each selected loadcase for each joint.
Summary report number 4 comprises the three worst unity checks for each selected joint, together with
the distribution of unity check values. The distribution provides information on the number of unity
checks exceeding an upper limit (default 1.0), less than a lower limit (default 0.5), and the number in
the mid range.
The BEAMST commands applicable to the DS44 JOIN command deck are given in Table 7.2: DS449 JOIN
Commands (p. 361) below and described in detail in BEAMST Command Reference (p. 51). An example
data file is given in Example 7.2: Example of a DS44 JOIN data file (p. 362).
Table 7.2: DS449 JOIN Commands
Command
Description
Usage
DS449 JOIN
DS449 joint check header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
MCOF
Partial Material Coefficient
GROU
Joint numbers to be reported
ELEM
Joint type and brace element definition
SECT
Secondary members to be ignored in checks
SECO
Secondary members
DESI
Defines design section properties
PROF
Section profiles for use in design
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BEAMST DS44 Theory
Command
Description
Usage
Note
GAPD
Define default gap dimension
STUB
Tubular member’s end stub dimensions
CASE
Basic loadcases to be reported
C
2
COMB
Define a combined loadcase for processing
C
2
CMBV
Define a combined loadcase for processing
C
2
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 7.2: Example of a DS44 JOIN data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
DS449 JOIN
*
* Investigate all joints in the model except where
* only one element is connected
*
JOINT ALL
NOT JOINTS 1315 1355 5110 5150
*
* Ignore dummy elements
*
SECONDARY ELEMENTS 801 802
UNIT KN M
*
* Change tubular dimensions for one element
*
AUGMENT TUB 1.0 0.05 ELEM 131
*
* Examine four load combinations
*
SELE 10 Extreme Wave + Dead Loads + Topside Loads (action comb a)
COMB 10 0.75 1 1.0 3 1.3 4
SELE 11 Extreme Wave + Dead Loads + Topside Loads (action comb b)
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DS449 Joint Checks (DS44 JOIN)
COMB 11 1.3 1 1.0 3 1.0 4
SELE 12 Extreme Wave + Dead Loads + Topside Loads (action comb c)
COMB 12 1.0 1 1.0 3 1.0 4
SELE 13 Extreme Wave + Dead Loads + Topside Loads (action comb d)
COMB 13 0.75 1 1.0 3 1.0 4
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Specify the chord elements for one of the joints
*
CHORD 1130 122 123
*
* Set some joints as being Y
*
TYPE.OF.JOINT 1130 Y 102
TYPE.OF.JOINT 1130 Y 103
*
* Ask explicitly for all reports
*
PRIN XCHK UNCK SUNI N MM SUM3 BOTH SUM4 BOTH
END
STOP
7.2.2. NPD JOIN Unity Check Report
The final column is reserved for messages. These may be summarized as follows:
***
Unity check value exceeds unity
**
Unity check value exceeds 0.9
NO
UNI
The joint geometry does not satisfy the criteria specified in D.2.3 (Ref. 9)
CHK
7.2.3. DS449 JOIN Nomenclature
DS449 JOIN uses the following nomenclature:
7.2.3.1. DS449 JOIN Nomenclature - Dimensional
7.2.3.2. DS449 JOIN Nomenclature - Acting Forces and Stresses
7.2.3.3. DS449 JOIN Nomenclature - Allowable Stresses and Unity Checks
7.2.3.4. DS449 JOIN Nomenclature - Parameters
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7.2.3.1. DS449 JOIN Nomenclature - Dimensional
D
Chord diameter
R
Chord radius
T
Chord thickness
d
Brace diameter
t
Brace thickness
g
K joint gap
A
Cross-sectional area of the brace
S
Section modulus of the brace
β
Ratio between the diameter of the brace and chord d/D
γ
Ratio between the chord radius and thickness R/T
θ
Angle between brace and chord
τ
Ratio between the thickness of the brace and chord t/T
7.2.3.2. DS449 JOIN Nomenclature - Acting Forces and Stresses
P
Axial force
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DS449 Joint Checks (DS44 JOIN)
Mip
Design in-plane bending moment in brace
Mop
Design out-of-plane bending moment in brace
fax
Axial stress
fip, fop
In-plane or out-of-plane bending stress
7.2.3.3. DS449 JOIN Nomenclature - Allowable Stresses and Unity Checks
PCRax
Critical axial load capacity for joint
MCRip, MCRCRop
Critical capacity for in-plane and out-of-plane moments
PVax
Joint capacity under axial load
MVip, MVop
Joint capacity for in-plane and out-of-plane moments
fCHORD
Yield stress for chord
UCax
Axial unity check
UCip, UCop
In-plane and out-of-plane bending moment check
UCBN
Combined axial and bending moment check
UCCO
Chord load carrying capacity check
7.2.3.4. DS449 JOIN Nomenclature - Parameters
Cax
parameter for critical load capacity of a joint as regards axial load
Cip, Cop
parameter for critical load capacity of a joint as regards in-plane and out-of-plane moments
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7.2.4. DS449 Joint Checks
Clause/(Eqn)
Joint Checks
Message
7.2.4.1. DS449 JOIN - Partial Material Coefficients
Clause/(Eqn)
Partial Material Coefficients
Message
7.2.4.2. DS449 JOIN - Critical Load Capacity
Clause/(Eqn)
366
Critical Load Capacity
Message
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DS449 Joint Checks (DS44 JOIN)
Clause/(Eqn)
Critical Load Capacity
Message
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7.2.4.3. DS449 JOIN - Joint Capacity
Clause/(Eqn)
Joint Capacity
Message
7.2.4.4. DS449 JOIN - Unity Checks
Clause/(Eqn)
368
Unity Check Values
Message
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Chapter 8: BEAMST NPD Theory
The NPD command in BEAMST is used to request member and joint checks to the Norwegian standards
NPD (Ref. 6) and NS3472 (Ref. 7).
The NPD and NS3472 codes specify ultimate limit state compliance checks and utilize the partial coefficient method. In keeping with this principle, applied loads must be multiplied by appropriate factors,
as defined in the code of practice (NPD, Regulations for structural design of load bearing structures intended for exploitation of petroleum resources, Section 4, and NS3472, Section 4.2, Design load or
factored load), to develop the design load case combinations necessary for processing. Where non-linear
pile analysis is undertaken (using SPLINTER) the design loads must be applied to the pile model to account for the increased non-linearity this introduces. In situations where a non-linear pile analysis has
not been carried out, the design loads may be produced using the COMB or CMBV commands utilizing
the required load factors. The value of the partial material coefficient is as specified in NPD.
Two types of check are available, member checks and joint checks, and these are requested using the
MEMB and JOIN subcommands respectively.
8.1. NPD and NS3472 Member Checks (NPD MEMB)
This section discusses the following topics:
8.1.1. NPD MEMB Overview
8.1.2. NPD MEMB Unity Check Report
8.1.3. NPD MEMB Nomenclature
8.1.4. NPD MEMB - Methods of von Mises stress calculation for NPD code checks
8.1.5. NPD MEMB - NPD and NS3472 Ultimate Limit State Compliance Checks
8.1.6. NPD 1992 Member Checks - Tubular Members
8.1.7. NPD Member Checks - Non-Tubular Members
8.1.1. NPD MEMB Overview
The MEMB subcommand is used to request ultimate limit state yield and buckling compliance checks
for tubular, I-shaped and hollow rectangular member types. For tubular members, checks are performed
to NPD whenever possible. When appropriate clauses do not exist in NPD, checks are performed to
NS3472. All other members are checked to NS3472. At present local buckling of plates is checked only
for tubular elements.
Elements may be selected on a group or element number basis using the GROU and ELEM commands
respectively. Loadcases from the preceding structural analysis may be selected for processing using the
CASE, COMB or CMBV commands. Acting and ultimate stresses/forces are calculated and design checks
are performed at element ends, at each change of section for stepped beams and at each user defined
section position (SECT). Various member and section properties may be defined using the DESI, PROF,
YIEL, EFFE, UNBR and ULCF commands. The units of all input data must be specified using the UNIT
command.
A feature of the NPD code is that the hydrostatic collapse check is performed at the same time as the
local buckling checks and a separate HYDR report is not necessary. If the WAVE, ELEV, MOVE and GRAV
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subcommands appear in the NPD MEMB command data block, BEAMST will automatically calculate the
hydrostatic stresses and perform the appropriate design checks.
The global buckling check of NS3472 requires the evaluation of an equivalent moment for each element.
This value is based on the end moments and the maximum free bending moment occurring along the
member and corresponds to the CMY/Z factors in the AISC/API checks. In order to maximize the number
of points at which the internal bending moments are calculated the SEAR command may be used.
Output reports are requested using the PRIN command. One set of output reports is printed for each
selected element in a similar manner to the AISC/API output. Member property, force and stress reports
are requested using the PROP, FORC and STRE subcommands respectively. The unity check report is
requested with the UNCK subcommands. For convenience this report is presented in the form of two
tables, the first for local element checks and the second for global buckling checks. Stresses are reported
in the local element checks and output units may be specified using the SUNI subcommand. Forces are
reported in the global buckling checks and output units may be specified using the FUNI subcommand.
Four summary reports are available:
Summary report 1 is requested with the PRIN SUM1 command and gives the highest local buckling,
global buckling and yield unity check values for each element.
Summary report 2 is requested with the PRIN SUM2 command and gives the highest buckle check and
all unity checks at the section with the highest yield combined stress unity check for each element.
Summary report 3 is requested with the PRIN SUM3 command and consists of the highest unity check
for each selected loadcase for each element selected.
Summary report 4 is requested with the PRIN SUM4 command and provides the three worst unity checks
for each selected group, together with the distribution of unity check values. The distribution provides
information on the number of unity checks exceeding an upper limit (default 1.0), less than a lower
limit (default 0.5), and the number in the mid-range.
The total buckling check of NPD/NS3472 requires the evaluation of equivalent moments based on the
values of the end moments and the maximum free bending moment. In order that the maximum free
bending moment is estimated properly it is necessary to specify at least one section along the beam,
preferably at the mid. The free bending moment values are reported at each section in the element
force report.
The BEAMST commands applicable to the NPD MEMB command are in Table 8.1: NPD MEMB Commands (p. 370) below and are described in detail in BEAMST Command Reference (p. 51). An example
data file is given in Example 8.1: Example of a NPD MEMB ED92 data file (p. 372).
Table 8.1: NPD MEMB Commands
Command
Description
Usage
API WSD ALLO
NPD MEMB
C
UNIT
Units of length and force
YIEL
Yield stress
MCOF
Partial material coefficient
1
C
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Note
NPD and NS3472 Member Checks (NPD MEMB)
Command
Description
Usage
Note
ELEV
Water depth and density
C
2
MOVE
Water axis origin in global structure axis system
C
WAVE
Wave height and period
GRAV
Gravitational acceleration relative to structure axis system
GROU
Groups to be reported
C
3
ELEM
Elements to be reported
C
3
SECT
Sections to be reported
SEAR
Search other sections in addition to those requested on
the SECT command for maximum forces and stresses
DESI
Defines design section properties
C
4
PROF
Section profiles for use in design
EFFE
Effective lengths/factors
PHI
Loadcase dependent parameter for lateral buckling
UNBR
Unbraced lengths of element
ULCF
Unbraced length of compression flange
CASE
Basic loadcases to be reported
C
5
COMB
Define a combined loadcase for processing
C
5
CMBV
Define a combined loadcase for processing
C
5
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
2
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. Compulsory only if hydrostatic pressure effects to be examined.
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3. At least one GROUP or ELEM command must be included.
4. Compulsory for non-tubulars unless sections have been used for all elements to be processed in the
preceding analyses.
5. At least one CASE, CMBV or COMB command must be included.
Example 8.1: Example of a NPD MEMB ED92 data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
NPD ED92 MEMB
*
* Horizontal plan bracing level -50 m
*
GROUP 1
UNIT KN M
*
* Change tubular dimensions for one element
*
DESI TUB 1.0 0.05 ELEM 131
*
* Examine two load combinations
*
SELE 10 Extreme Wave + Dead Loads + Topside Loads (Comb a)
COMB 10 0.7 1 1.3 3 1.3 4
SELE 11 Extreme Wave + Dead Loads + Topside Loads (Comb b)
COMB 11 1.3 1 1.0 3 1.0 4
*
* Include hydrostatic checks
*
ELEVATION 0.0 -50.0 1.025
GRAVITY 0.0 0.0 -9.81
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Main plan bracing members use effective length
* coefficient of 0.8
* Note that the element definition overrides the
* group definition irrespective of order
*
EFFECTIVE.LENGTH 0.8 ELEMENTS 105 106
EFFECTIVE.LENGTH 0.8 ELEMENTS 101 TO 104
EFFECTIVE.LENGTH 0.8 ELEMENTS 107 TO 110
EFFECTIVE.LENGTH 1.0 GROUP 1
*
* Out of plane unbraced lengths need redefining
*
UNBRACED FACT 2.0 1.0 ELEM 105 106
UNBRACED LENG 15.0 7.5 ELEM 102 103
*
* Check mid-span sections
*
SECT 0.5 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP UNCK FORC SUNI N MM SUM1 SUM2 SUM3 SUM4
END
STOP
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NPD and NS3472 Member Checks (NPD MEMB)
8.1.2. NPD MEMB Unity Check Report
The column headed Messages may contain one of the following:
FAIL
Code check failure.
**
Unity check value exceeds 0.9
***
Unity check value exceeds 1.0
SLRF
Member slenderness ratio exceeds 250
CL-4
Member belongs to design class 4 of NS3472, Figure 5.2.2. This message appears if:
8.1.3. NPD MEMB Nomenclature
NPD MEMB uses the following nomenclature:
8.1.3.1. NPD MEMB Nomenclature - Dimensional
8.1.3.2. NPD MEMB Nomenclature - Acting Forces and Stresses
8.1.3.3. NPD MEMB Nomenclature - Allowable Stresses and Unity Checks
8.1.3.4. NPD MEMB Nomenclature - Parameters
8.1.3.1. NPD MEMB Nomenclature - Dimensional
(a) Rolled Sections
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(b) Welded Sections
A
Cross-sectional area
Ay
Y shear area
Az
Z shear area
Iz
Sectional inertia, major axis
Iy
Sectional inertia, minor axis
Ix
Sectional inertia, torsion
Sz
Major axis elastic section modulus
Sy
Minor axis elastic section modulus
ry
Radius of gyration about y axis
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NPD and NS3472 Member Checks (NPD MEMB)
rz
Radius of gyration about z axis
8.1.3.2. NPD MEMB Nomenclature - Acting Forces and Stresses
N
Axial force
My, Mz
Bending moment about y or z axis
Qy, Qz
Shear force along y and z axis
Mx
Torque
fa
Axial stress
fb
Bending stress
fh
Hoop stress
fvm
von Mises stress
fvt
Torsional shear stress
fvb
Flexural shear stress due to both y and z shear forces
fvy
Flexural shear stress along y axis
fvz
Flexural shear stress along z axis
8.1.3.3. NPD MEMB Nomenclature - Allowable Stresses and Unity Checks
Fy
Yield stress
fky, fkz
Buckling stress
Nkdy, Nkdz
Buckling design resistances about y and z axes
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Nedy, Nedz
Euler buckling resistances about y and z axes
Mdy, Mdz
Moment capacities about y and z axes, excluding buckling effects
Ntd
Torsional buckling resistance
Mvd
Lateral buckling design moment
UCab
Combined axial and bending check
UCvy
Shear yield check along y axis
UCvz
Shear yield check along z axis
UCvm
von Mises unity check
UCby
Global buckling check about y axis
UCbz
Global buckling check about z axis
8.1.3.4. NPD MEMB Nomenclature - Parameters
E
Young's modulus
G
Shear Modulus
φ
Factor used in computing the ideal buckling moment
ky, kz
effective length factors
Ly
unbraced length for minor axis bending
Lz
unbraced length for major axis bending
376
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NPD and NS3472 Member Checks (NPD MEMB)
8.1.4. NPD MEMB - Methods of von Mises stress calculation for NPD code
checks
• Tubular Members (NPD 1992 Edition)
• I-Sections
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378
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NPD and NS3472 Member Checks (NPD MEMB)
• Hollow Rectangular Sections
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8.1.5. NPD MEMB - NPD and NS3472 Ultimate Limit State Compliance Checks
380
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NPD and NS3472 Member Checks (NPD MEMB)
The design load effects are member forces or stresses resulting from a combination of design loads
factored using partial load coefficients as specified in NS3479 (Ref. 8.).
Cross sections are assumed to be class 1, 2 or 3 as defined in NS 3472 clause 5.2.2.1. If a cross-section
is of class 4 a message is printed in the local unity check report to signify that local buckling may occur
before yielding in the most extreme fiber.
8.1.6. NPD 1992 Member Checks - Tubular Members
This section discusses the following topics:
8.1.6.1. NPD MEMB - Material and Structural Coefficients
8.1.6.2. NPD MEMB - von Mises Unity Check
8.1.6.3. NPD MEMB - Elastic Buckling Resistance for Unstiffened Cylindrical Shells
8.1.6.4. NPD MEMB - Global Buckling Check
8.1.6.1. NPD MEMB - Material and Structural Coefficients
Clause/(Eqn)
Material and Structural Coefficients
8.1.6.2. NPD MEMB - von Mises Unity Check
Clause/(Eqn)
von Mises Unity Check
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8.1.6.3. NPD MEMB - Elastic Buckling Resistance for Unstiffened Cylindrical Shells
Clause/(Eqn)
382
Elastic Buckling Resistance for Unstiffened Cylindrical Shells
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NPD and NS3472 Member Checks (NPD MEMB)
Clause/(Eqn)
Elastic Buckling Resistance for Unstiffened Cylindrical Shells
8.1.6.4. NPD MEMB - Global Buckling Check
Clause/(Eqn)
Global Buckling Check
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Clause/(Eqn)
384
Global Buckling Check
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NPD and NS3472 Member Checks (NPD MEMB)
Clause/(Eqn)
Global Buckling Check
8.1.7. NPD Member Checks - Non-Tubular Members
This section discusses the following topics:
8.1.7.1. NPD MEMB - Material and Structural Coefficients
8.1.7.2. NPD MEMB - Global Buckling
8.1.7.3. NPD MEMB - Torsional Buckling
8.1.7.4. NPD MEMB - Lateral Buckling
8.1.7.5. NPD MEMB - Unity Check Values
8.1.7.1. NPD MEMB - Material and Structural Coefficients
Clause/(Eqn)
Material and Structural Coefficients
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8.1.7.2. NPD MEMB - Global Buckling
Clause/(Eqn)
386
Global Buckling
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Clause/(Eqn)
Global Buckling
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Clause/(Eqn)
Global Buckling
8.1.7.3. NPD MEMB - Torsional Buckling
Clause/(Eqn)
388
Torsional Buckling
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NPD and NS3472 Member Checks (NPD MEMB)
Clause/(Eqn)
Torsional Buckling
8.1.7.4. NPD MEMB - Lateral Buckling
Clause/(Eqn)
Lateral Buckling
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Clause/(Eqn)
Lateral Buckling
8.1.7.5. NPD MEMB - Unity Check Values
Clause/(Eqn)
390
Unity Check Values
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NPD Joint Checks (NPD JOIN)
Clause/(Eqn)
Unity Check Values
8.2. NPD Joint Checks (NPD JOIN)
This section discusses the following topics:
8.2.1. NPD JOIN Overview
8.2.2. NPD JOIN Unity Check Report
8.2.3. NPD JOIN Nomenclature
8.2.4. NPD 1992 Joint Checks
8.2.1. NPD JOIN Overview
The JOIN subcommand requests that punching shear joint checks be performed to NPD regulations.
Joint selection and classification is similar to that for the API punching shear check (API PUNC). Joints
are selected with the JOIN command and elements may be excluded from joints with the SECO command.
The STUB command may be used to redefine the member thickness and outside diameter at a joint.
Joints are automatically classed as K, T or Y depending on the joint geometry as follows.
1. The chord member is the member with the greatest outside diameter.
2. If two or more potential chord members have equal diameters, BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
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3. In the case of two or more potential chord members with equal diameters and wall thicknesses, the first
two encountered as shown in the Cross Check Report will be considered.
4. If the CHORd command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
BEAMST selects ‘simple’ joint (brace-chord pair) ‘types’ as follows:
1. Brace members ‘perpendicular’ to the chord members (smaller included angle greater than or equal to
80 degrees) as T joints.
2. Single non-‘perpendicular’ braces are classified as Y joints. Two non-perpendicular braces on the same
side of the chord are classified as K joints.
3. Cross (X) joints must be user specified.
4. In the case of user defined K and X joints, no search is performed for a second brace member in the
same brace-chord plane as the first brace.
5. Brace members specified on joint TYPE commands are automatically selected as braces in the above
brace-chord member selection process.
6. No conflict between CHORd command specified members and brace members specified on joint TYPE
commands is allowed.
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
A punching shear unity check report may be requested by including UNCK in the PRIN command. The
report gives details of geometric parameters, acting and critical stresses and unity check values.
Summary report 3 comprises the highest unity check for each selected loadcase for each joint.
Summary report 4 comprises the three worst unity checks for each selected joint, together with the
distribution of unity check values. The distribution provides information on the number of unity checks
The BEAMST commands applicable to the NPD JOIN command are given in Table 8.2: NPD JOIN Commands (p. 392) below and described in detail in BEAMST Command Reference (p. 51). An example data
file is given in Example 8.2: Example of a NPD ED92 JOIN data file (p. 393).
Table 8.2: NPD JOIN Commands
Command
Description
Usage
NPD JOIN
NPD joint check header command
C
UNIT
Units of length and force
1
C
YIEL
Yield stress
MCOF
Partial material coefficient
JOIN
Joint numbers to be reported
392
Note
C
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NPD Joint Checks (NPD JOIN)
Command
Description
Usage
Note
CHOR
Chord elements at a joint
SECO
Secondary elements to be ignored in checks
DESI
Defines design section properties
PROF
Section profiles for use in design
STBU
Tubular member end stub dimensions
CASE
Basic loadcases to be reported
C
2
COMB
Define a combined loadcase for processing
C
2
CMBV
Define a combined loadcase for processing
C
2
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 8.2: Example of a NPD ED92 JOIN data file
SYSTEM DATA AREA 100000
TEXT BEAMST USER MANUAL EXAMPLE STRUCTURE T0847
JOB POST
PROJECT MANU
COMPONENT PILE JACA
OPTION GOON
END
NPD ED92 JOIN
*
* Investigate all joints in the model except where
* only one element is connected
*
JOINT ALL
NOT JOINTS 1315 1355 5110 5150
*
* Ignore dummy elements
*
SECONDARY ELEMENTS 801 802
UNIT KN M
*
* Change tubular dimensions for one element
*
DESIGN TUB 1.0 0.05 ELEM 131
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*
* Examine two wave cases
*
SELE 10 Extreme Wave + Dead Loads + Topside Loads (Comb a)
COMB 10 0.7 1 1.3 3 1.3 4
SELE 11 Extreme Wave + Dead Loads + Topside Loads (Comb b)
COMB 11 1.3 1 1.0 3 1.0 4
*
* Yield Value Constant for all elements
*
YIELD 3.5E05 ELEM ALL
*
* Specify the chord elements for one of the joints
*
CHORD 1130 122 123
*
* Set some joints as being Y
*
TYPE.OF.JOINT 1130 Y 102
TYPE.OF.JOINT 1130 Y 103
*
* Ask explicitly for all reports
*
PRIN XCHK UNCK SUNI N MM SUM3 BOTH SUM4 BOTH
END
STOP
8.2.2. NPD JOIN Unity Check Report
The column headed Messages may contain one of the following:
FAIL
Code check failure.
**
Unity check value exceeds 0.9
***
Unity check value exceeds 1.0
NOCK
No unity check is calculated as θ < 200
RNGE
The limits of validity of the punching shear formulae have been exceeded
8.2.3. NPD JOIN Nomenclature
NPD JOIN uses the following nomenclature:
8.2.3.1. NPD JOIN Nomenclature - Dimensional
8.2.3.2. NPD JOIN Nomenclature - Acting Forces and Stresses
8.2.3.3. NPD JOIN Nomenclature - Allowable Stresses, Capacities and Unity Checks
8.2.3.4. NPD JOIN Nomenclature - Parameters
394
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NPD Joint Checks (NPD JOIN)
8.2.3.1. NPD JOIN Nomenclature - Dimensional
D
Chord diameter
R
Chord radius
T
Chord thickness
d
Brace diameter
t
Brace thickness
g
K joint gap
β
Ratio between the diameter of the brace and chord d/D
γ
Ratio between the chord thickness and radius T/R
θ
Angle between brace and chord
8.2.3.2. NPD JOIN Nomenclature - Acting Forces and Stresses
N
Design axial force in brace
Mip
Design in-plane bending moment in brace
Mop
Design out-of-plane bending moment in brace
fac
Design axial stress in chord, tension positive
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fby
Design bending stress about y axis in chord
fbz
Design bending stress about z axis in chord
8.2.3.3. NPD JOIN Nomenclature - Allowable Stresses, Capacities and Unity Checks
fy
Chord yield stress
Nk
Characteristic axial load capacity
Mipk
characteristic in-plane bending moment capacity
Mopk
characteristic out-of-plane bending moment capacity
UCax
axial unity check
UCip
in-plane bending moment check
UCop
out-of-plane bending moment check
UCcmb
combined axial and bending moment check
8.2.3.4. NPD JOIN Nomenclature - Parameters
Qf
Factor to account for the nominal longitudinal stress in the chord
Qu, Qg, Qβ
Shear Modulus
8.2.4. NPD 1992 Joint Checks
This section discusses the following topics:
8.2.4.1. NPD JOIN - Nominal Longitudinal Chord Stress
8.2.4.2. NPD JOIN - Characteristic Capacities
8.2.4.3. NPD JOIN - Unity Checks
396
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NPD Joint Checks (NPD JOIN)
8.2.4.1. NPD JOIN - Nominal Longitudinal Chord Stress
Clause/(Eqn)
Nominal Longitudinal Chord Stress
8.2.4.2. NPD JOIN - Characteristic Capacities
Clause/(Eqn)
Characteristic Capacities
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Clause/(Eqn)
Characteristic Capacities
8.2.4.3. NPD JOIN - Unity Checks
Clause/(Eqn)
398
Unity Checks
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Chapter 9: BEAMST NORSOK Theory
The NORSOK command data block is used to request member allowable, hydraulic collapse and joint
checking to the NORSOK code of practice (Ref. 24).
9.1. NORSOK Member Code Check (NORS MEMB)
This section discusses the following topics:
9.1.1. NORS MEMB Overview
9.1.2. NORSOK MEMB Unity Check Report
9.1.3. NORS MEMB Nomenclature
9.1.4. NORSOK Design Strengths and Unity Checks
9.1.1. NORS MEMB Overview
The NORS MEMB header command in BEAMST is used to request member allowable checks to the
NORSOK structural design standard (Ref. 24).
The code checks are only available for tubular members, including beam elements that have been assigned circular tubular sections in the structural analysis.
The NORSOK code of practice is written in terms of material yield strengths, so YIELd commands are
necessary to specify the material strengths of all members that are to be checked. The units of the yield
strength must be those of the UNIT command (BEAMST Command Reference (p. 51)).
Members may be selected for processing by member or group number. Additional commands available
for defining the topological characteristics of the members include the EFFE, and UNBR commands.
Loadcases from the preceding structural analysis may be selected for processing using the CASE command. New cases may be generated as combinations of the existing cases with the COMB and CMBV
commands.
The SECT command may be used to specify the number of intermediate points along a member at
which member forces and moments are to be evaluated, checked and reported. These are in addition
to the values automatically output at the member ends and any changes of cross-section properties.
For the code checks it is necessary to ensure the maximum acting bending moments and stresses are
evaluated. Since does not necessarily occur at any of the selected locations, BEAMST has a SEARch
command which causes the moments and stresses to be evaluated at every L/4 and L/6 (L = beam
length) for prismatic and stepped beams respectively. These locations are in addition to those selected:
the results at these additional locations are only presented if they give the maximum moments or
stresses on the members.
The output of reports is controlled by the PRIN command, with the appropriate parameters for the required reports. The PRIN command is also used to request the various available summary reports and
to set exceedence values for the unity checks. Two summary reports are available:
Summary report 1 is requested with the PRIN SUM1 subcommand and gives the highest local buckling,
global buckling and yield unity checks for each requested element.
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Summary report 3 is requested with the PRIN SUM3 subcommand and gives the highest unity check
for each loadcase for each selected element.
A list of the commands available for the NORSOK member code checks is given in Table 9.1: NORSOK
MEMB Commands (p. 400) below and described in detail in BEAMST Command Reference (p. 51). An
example data file is given in Example 9.1: Example of a NORSOK MEMB data file (p. 401).
Table 9.1: NORSOK MEMB Commands
Command
Description
Usage
NORS MEMB
NORSOK allowable force header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
MCOF
Partial Material Coefficient
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SEAR
Search for maximum forces and stresses
SECO
Secondary members
DESI
Defines design section properties
PROF
Section profiles for use in design
EFFE
Effective lengths/factors
CMY/CMZ
Amplification reduction factors Cmy/Cmz
UNBR
Unbraced lengths of element
ULCF
Length of tubular members between stiffening rings,
diaphragms, etc.
CASE
Loadcases to be reported
C
3
COMB
Define a combined loadcase for processing
C
3
CMBV
Define a combined loadcase for processing
C
3
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
400
C
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NORSOK Member Code Check (NORS MEMB)
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. At least one CASE, CMBV or COMB command must be included.
Example 9.1: Example of a NORSOK MEMB data file
SYSTEM DATA AREA 2000000
TITLE Beamst NORSOK verification test t1835be1.dat
***************************************************************
TEXT
TEXT NORSOK TEST FOR MEMBERS’ CAPABILITY
TEXT
***************************************************************
JOB OLD POST
STRUCTURE N835
OPTIONS GOON
FILES M835
UNITS STRESS N MM
END
NORS ED98 MEMB
PROJECT N835
UNITS N M
TEXT - ELEMENTS AND YIELD STRESSES
ELEM 501 502 503
TEXT - COMBINATIONS
SELE 2 basic loading x 1.0
COMB 2 1.000 1
SELE 3 basic loading x 0.7
COMB 3 -0.700 1
SELE 4 basic loading x 1.3
COMB 4 1.300 1
TEXT
TEXT - GEOMETRY
TEXT
AUGM 0 2.0000 0.0200 ELEM 501
YIEL 200000000. ELEM 501
AUGM 1 2.5000 2.1000 0.0250 0.0200 ELEM 502
GEOM 0.13960000 0.50000000E-01 0.90500000E-01 0.22550833E-04
: 0.30727053E-01 0.16124172 ELEM 502
YIEL 200000000. ELEM 502 503
TEXT
TEXT - SECTIONS
TEXT
SECT 0.001 0.500 0.999 ELEM 501
SECT 0.001 0.500 0.999 ELEM 502
TEXT
TEXT - PARAMETERS
TEXT
CMY 0.850 ELEM 501
CMZ 0.850 ELEM 501
EFFE 1.000 1.000 ELEM 501
UNBR 30.000 30.000 ELEM 501
CMY 0.850 ELEM 502
CMZ 0.850 ELEM 502
EFFE 1.000 1.000 ELEM 502
UNBR 30.000 30.000 ELEM 502
CMY 0.850 ELEM 503 CMZ 0.850 ELEM 503
EFFE 1.000 1.000 ELEM 503
UNBR 0.000 0.000 ELEM 503
PRINT UNCK SUM1 SUM3
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END
STOP
9.1.2. NORSOK MEMB Unity Check Report
The unity check report is presented on an element by element basis. The header line displays the element
number, the associated node numbers, the element group number and the units in use. The results are
printed for each selected position (section) along the element for each loadcase in turn. The first columns
of the report define the loadcase, section number and position as a ratio of the element’s length.
The allowable forces and moments for axial, shear and bending (in local Y and Z axes) are presented
in the next columns of the report. These are preceded by an alphanumeric descriptor (CODE) that indicates the derivation of each of the allowable forces. These descriptors are of the form:
T.XVYZ or C.XVYZ
T or C defines whether the member is in tension or compression. XVYZ are individual alpha codes that
relate to the axial (X), shear (V) and bending (Y, Z) forces or moments. These alpha codes specify the
design code clause or equation used to evaluate the allowable forces or moments and are defined in
Table 9.2: NORSOK HYDR Commands (p. 413).
9.1.3. NORS MEMB Nomenclature
NORS MEMB uses the following nomenclature:
9.1.3.1. NORS MEMB Nomenclature - Dimensional
9.1.3.2. NORS MEMB Nomenclature - Acting Section Stresses
9.1.3.3. NORS MEMB Nomenclature - Design Strengths and Unity Checks
9.1.3.4. NORS MEMB Nomenclature - Parameters
9.1.3.1. NORS MEMB Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
k
Effective length factor (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
402
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NORSOK Member Code Check (NORS MEMB)
L
Unbraced length of member (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
i
Radius of gyration (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
A
Cross sectional area
Ip
Polar moment of inertia
W
Elastic section modulus
Z
Plastic section modulus
9.1.3.2. NORS MEMB Nomenclature - Acting Section Stresses
Ns
Design axial force
Ms
Design bending moment (if subscripted with y or z, this relates to the appropriate local axis, if not it is
the maximum)
Vs
Design shear force
MTs
Design torsional moment
σc
Maximum combined design compressive stress
σp
Design hoop stress due to hydrostatic pressure
τTs
Shear stress due to design torsional moment
9.1.3.3. NORS MEMB Nomenclature - Design Strengths and Unity Checks
fy
Yield stress
NEy, NEz
Euler buckling resistance for y and z axes
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fcle
Characteristic elastic local buckling strength
fcl
Characteristic local buckling strength
fc
Column axial compressive strength
fd
Yield stress divided by material factor
fhe
Elastic hoop buckling strength
fm
Characteristic bending strength
fmRed
Characteristic bending strength divided by material factor
Nt
Design tension strength
Nc
Design compressive strength
MR
Design bending strength
VR
Design beam shear strength
MTR
Design torsion shear strength
Ncl
Design axial local buckling resistance
UCax
Axial unity check
UCvmax
Flexural shear unity check
UCTOR
Torsional shear unity check
UCby
Pure bending check about y axis
404
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NORSOK Member Code Check (NORS MEMB)
UCbz
pure bending check about z axis
UCbr
Pure resultant bending check
UCy
Combined axial tension and bending check
UCy1
Combined axial compressions and bending yield unity check (6.27)
UCy2
Combined axial compression and bending yield unity check (6.28)
UCsb
Combined shear and bending unity check
UCsbT
Combined shear, bending and torsion unity check
9.1.3.4. NORS MEMB Nomenclature - Parameters
E
Young's modulus
Cmy, Cmz
Moment amplification reduction factors
γm
Material factor
Column slenderness parameter (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
Stress parameter as defined by NORSOK equation (6.23)
9.1.4. NORSOK Design Strengths and Unity Checks
This section discusses the following topics:
9.1.4.1. Design Tension Strength, Nt
9.1.4.2. Design Compression Strength, Na
9.1.4.3. Design Bending Strength, MR
9.1.4.4. Design Shear Strengths, VR and MTR
9.1.4.5. Material Factor, γm
9.1.4.6. NORS MEMB - Unity Checks
9.1.4.7. NORS MEMB - Combined Forces
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9.1.4.1. Design Tension Strength, Nt
Clause/(Eqn)
Commentary
Code Message
Design Strength
9.1.4.2. Design Compression Strength, Na
Clause/(Eqn)
Commentary
Code Message
Characteristic elastic local buckling strength, fcle
Characteristic local buckling strength, fcl
Column slenderness parameter,
Column
axial compressive
strength,
fc
406
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NORSOK Member Code Check (NORS MEMB)
Clause/(Eqn)
Commentary
Code Message
9.1.4.3. Design Bending Strength, MR
Clause/(Eqn)
Commentary
Code Message
Characteristic bending strength, fm
9.1.4.4. Design Shear Strengths, VR and MTR
Clause/(Eqn)
Commentary
Code Message
Beam Shear
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407
BEAMST NORSOK Theory
Clause/(Eqn)
Commentary
Code Message
Torsional Shear
9.1.4.5. Material Factor, γm
Clause/(Eqn)
408
Commentary
Code Message
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NORSOK Member Code Check (NORS MEMB)
9.1.4.6. NORS MEMB - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
Shear
Pure Bending
9.1.4.7. NORS MEMB - Combined Forces
Clause/(Eqn)
Commentary
Code Message
Axial tension and bending
Axial compression and bending
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409
BEAMST NORSOK Theory
Clause/(Eqn)
Commentary
Code Message
Design axial local buckling resistance, Ncl
where
Euler buckling strengths, NEy, NEz
Shear and bending
Shear, bending and torsion
410
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NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
Clause/(Eqn)
Commentary
Code Message
9.2. NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
This section discusses the following topics:
9.2.1. NORS HYDR Overview
9.2.2. NORSOK Hydrostatic Collapse Member Unity Check Report
9.2.3. NORS HYDR Nomenclature
9.2.4. NORSOK Unity Checks
9.2.1. NORS HYDR Overview
The NORS HYDR is used to request that hydrostatic pressure, allowable stresses, member actions, unity
checks and combined stress hydrostatic collapse unity checks be performed according to the NORSOK
design recommendations (Ref. 24). This check is implemented in BEAMST for tubular elements, or other
element types that have been assigned tubular sections in the structural analysis.
Members may be selected for processing by element and/or group. The member section dimensions
may be redefined using the DESI and/or PROF commands to modify the diameter and/or the thickness.
Further commands are available for defining topological characteristics of the members (EFFE, UNBR
and ULCF) and specifying members that are classified as secondary (SECO).
The SECT command may be used to define intermediate points along an element at which member
forces and moments are to be evaluated, checked and reported. These are in addition to the results
automatically printed at member end points and any positions of step-change of cross-section along
the member. Alternatively the SEARch command may be used which requests that moments and stresses
are to be evaluated at specified locations along the beam, but only reported if they give a maximum
force, stress or utilization. These locations are in addition to those selected using the SECT command.
The NORSOK code of practice allows hydrostatically induced stresses to be considered in alternate ways.
In “Method A” the stresses due to end-cap forces are presumed to be excluded from the raw element
forces. Conversely in “Method B” the stresses due to end-cap forces are presumed to be included.
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BEAMST NORSOK Theory
Both of these methods are implemented in BEAMST. The user should select the appropriate method
for the member force and moment data that are being supplied to BEAMST. If the user had requested
“rigorous buoyancy” to be included in a previous ASAS-WAVE analysis, by using the option BRIG on the
OPTIONS data line, then Method B is appropriate. This should be selected by either specifying the BRIG
option in BEAMST or by including a BRIG command in the command deck for BEAMST. Conversely, if
the user did not specify BRIG in the preceding ASAS-WAVE analysis then the BRIG option should be
omitted from the BEAMST options. The inclusion of a BRIG OFF command has the same effect. By default
the end-cap forces are assumed to be excluded from the analysis, i.e., BRIG is OFF unless specifically
requested. In ASAS-WAVE the BRIG option calculates the member axial forces due to hydrostatic effects.
These are then passed to ASAS through the generated wave load data.
The calculation of hydrostatic pressure requires a knowledge of the position of each member with respect
to still water level, tide height, wave height and length as well as details of the sea medium. Various
commands are available in BEAMST to define these data. First a reference frame must be specified for
the (sea) water axes and its origin in terms of the jacket reference frame defined (i.e., the global co-ordinate system used in the preceding ASAS analysis) using a MOVE command. See section 3.4 and Ref.
14 for more details. This command is optional and if omitted the wave and jacket axes are presumed
to coincide. Having defined the water axes origin, the relative orientations of the water and jacket axes
must follow. For example the jacket axes may be inclined to the water axes if the jacket is being analyzed
in a semi-submerged position. In order to convert pressure heads to hydrostatic pressure the acceleration
due to gravity in the vertical downwards (-Zwater) direction is required. If the components of the acceleration due to gravity are specified in terms of the jacket axes the water - jacket axes may be specified
in one operation.
The GRAVity command in BEAMST is available for this purpose and is compulsory for the NORSOK hydrostatic collapse check. The jacket and water axes are now fixed spatially and the only remaining information required for calculating the static head is that of the mean sea water level, sea bed level,
water density and tide height. These data are supplied on the compulsory ELEV command. Finally a
WAVE command may be issued to specify the wave height and period which enables prediction of the
wave-induced pressure components. This command is optional. If it is omitted then still water conditions
are assumed. For the calculation of the hydrostatic head the API recommendations are used to obtain
the wave length: this is calculated automatically by BEAMST on the basis of the water depth and wave
period using linear wave theory. Details of this procedure are given in API Allowable Stresses and Unity
Checks (p. 226).
All elements selected for hydrostatic collapse post-processing are assumed to be unflooded and unstiffened (i.e. the axial length of the cylinder between stiffening rings, diaphragms or end connections
is equal to the element length). The unstiffened length may be defined explicitly using the ULCF command. This command allows ring-stiffened tubulars to be checked for hydrostatic collapse between the
stiffening rings. The NORSOK hydrostatic code checks include some of the basic member interaction
checks and use is made of the unbraced length (UNBR) and effective length parameters (EFFE) together
with the amplification reduction factors Cmy and Cmz. It is, therefore, important that these terms are
supplied in a form consistent with a NORSOK MEMB check.
9.2.2. NORSOK Hydrostatic Collapse Member Unity Check Report
A detailed Unity Check Report incorporating beam section hydrostatic depth, member acting and allowable forces and stresses, membrane hoop and tension or compression collapse interaction unity checks
is available and may be printed using the PRIN UNCK command. A summary report is available:
Summary report 1 is requested with the PRIN SUM1 command and gives the highest unity check values
for each element.
412
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NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
The BEAMST commands applicable to the NORS HYDR collapse command data are given in
Table 9.2: NORSOK HYDR Commands (p. 413) below and are described in detail in BEAMST Command
Reference (p. 51). An example data file is given in Example 9.2: Example of a NORSOK HYDR data
file (p. 414).
Table 9.2: NORSOK HYDR Commands
Command
Description
Usage
NORS HYDR
NORSOK hydrostatic collapse header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
MCOF
Partial Material Coefficient
ELEV
Water depth and density
MOVE
Water axis origin in global structure axis system
WAVE
Wave height and period
GRAV
Gravitational acceleration relative to structure axis system
BRIG
Selects rigorous buoyancy method for calculation
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
DESI
Defines design section properties
PROF
Section profiles for use in design
ULCF
Length of tubular members between stiffening rings,
diaphragms, etc.
CASE
Basic loadcases to be reported
C
3
COMB
Define a combined loadcase for processing
C
3
CMBV
Define a combined loadcase for processing
C
3
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
C
C
Usage
C Compulsory command, but see notes below where applicable.
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413
BEAMST NORSOK Theory
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. At least one CASE, CMBV or COMB command must be included.
Example 9.2: Example of a NORSOK HYDR data file
SYSTEM DATA AREA 2000000
TEXT
TEXT NORSOK HYDROSTATIC COLLAPSE TEST EXAMPLE
TEXT JOB OLD POST
PROJECT N835
STRUCTURE N835
TEXT
TEXT NOTE PRECEDING ASAS-WAVE ANALYSIS HAD BRIG OPTION
TEXT
OPTIONS GOON NOBL BRIG
FILES Q835
END
NORS ED98 HYDR
TEXT
TEXT WATER POSITION AND WAVE DEFINITION
TEXT
MOVE 0.0 0.0 100.0
GRAV 0.0 0.0 -9.807
ELEV 30.0 0.0 1024.0
WAVE 1.0 10.0
UNITS N M
TEXT
TEXT - ELEMENTS AND YIELD STRESSES
TEXT
ELEM 681 682 683 684
TEXT
TEXT - COMBINATIONS OF LOAD
TEXT
SELE 2 basic loading x 1.0
COMB 2 1.000 1
SELE 3 basic loading x 0.7
COMB 3 -0.700 1
SELE 4 basic loading x 1.3
COMB 4 1.300 1
TEXT
TEXT - GEOMETRY
TEXT
AUGM 0 1.0000 0.0200 ELEM 681
YIEL 450000000. ELEM 681
AUGM 0 1.0000 0.0200 ELEM 682
YIEL 200000000. ELEM 682
AUGM 0 1.0000 0.0200 ELEM 683
YIEL 200000000. ELEM 683
AUGM 0 1.0000 0.0150 ELEM 684
YIEL 200000000. ELEM 684
TEXT
TEXT - SECTIONS
TEXT
SECT 0.001 0.300 0.500 0.700 0.900 ELEM 681
SECT 0.001 0.500 0.999 ELEM 682
SECT 0.001 0.500 0.999 ELEM 683
SECT 0.001 0.500 0.999 ELEM 684
TEXT
TEXT - PARAMETERS
TEXT
CMY 0.850 ELEM 681
CMZ 0.850 ELEM 681
EFFE 1.000 1.000 ELEM 681
UNBR 23.049 23.049 ELEM 681
CMY 0.850 ELEM 682
414
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NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
CMZ 0.850 ELEM 682
EFFE 1.000 1.000 ELEM 682
UNBR 23.049 23.049 ELEM 682
CMY 0.850 ELEM 683
CMZ 0.850 ELEM 683
EFFE 1.000 1.000 ELEM 683
UNBR 23.049 23.049 ELEM 683
CMY 0.850 ELEM 684
CMZ 0.850 ELEM 684
EFFE 1.000 1.000 ELEM 684
UNBR 0.000 0.000 ELEM 684
PRINT UNCK SUM1 SUNI N MM
END
STOP
9.2.3. NORS HYDR Nomenclature
NORS HYDR uses the following nomenclature:
9.2.3.1. NORS HYDR Nomenclature - Dimensional
9.2.3.2. NORS HYDR Nomenclature - Acting Section Forces and Stresses
9.2.3.3. NORS HYDR Nomenclature - Allowable Stresses and Unity Checks
9.2.3.4. NORS HYDR Nomenclature - Parameters
9.2.3.1. NORS HYDR Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
k
Effective length factor (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
Lu
Unstiffened length of member
L
Unbraced length of member (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
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415
BEAMST NORSOK Theory
i
Radius of gyration (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
9.2.3.2. NORS HYDR Nomenclature - Acting Section Forces and Stresses
σac
Design axial stress including effect of hydrostatic capped axial stress
σa
Design axial stress
σq
Capped end axial design compression due to external hydrostatic pressure
σmy, σmz
Design bending stress about local y and z axes
σp
Design hoop stress due to hydrostatic pressure
σm
Design bending stress
9.2.3.3. NORS HYDR Nomenclature - Allowable Stresses and Unity Checks
fh
Characteristic hoop buckling strength
fhe
Elastic hoop buckling strength
fm
Characteristic bending strength
fcl
Characteristic local buckling strength
fcle
Characteristic elastic local buckling strength
fc
Characteristic axial compressive strength
fclR
Design local buckling strength
fchR
Design axial compressive strength in the presence of external hydrostatic pressure
fmh
Design bending resistance in the presence of external hydrostatic pressure
416
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NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
fEy, fEz
Euler buckling strength for y and z axes
fy
Yield stress
UCc1,c2,c3
Combined axial (tension or compression), bending and hydrostatic pressure checks
UCh
Hoop compressive unity check
9.2.3.4. NORS HYDR Nomenclature - Parameters
E
Young’s modulus
Ch
Critical hoop buckling coefficient
γm
Material factor
Column slenderness parameter
Cmy, Cmz
Moment amplification reduction factors
9.2.4. NORSOK Unity Checks
In the hydrostatic collapse check the following assumptions are made:
1. All members are unflooded.
2. Out-of-roundness is assumed to be within API RP2B tolerance limits.
3. Wave crest is assumed to be directly above the beam section position under consideration.
4. Hydrostatic pressure is only considered for beam section positions below the static water level (=mean
water level + tide height + storm surge height).
5. The wave length, Lw, is adequately described by linear wave theory as follows:
a. If
(shallow water)
then
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417
BEAMST NORSOK Theory
b. Else if
and
(deep water)
then
c. Else Lw is obtained iteratively from
where:
• d = static water depth
• g = acceleration due to gravity
• Tw = wave period
9.2.4.1. NORS HYDR - Design Hydrostatic Pressure
Clause/(Eqn)
Commentary
Message
9.2.4.2. NORS HYDR - Limit Checks
Clause/(Eqn)
418
Commentary
Message
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NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
Clause/(Eqn)
Commentary
Message
9.2.4.3. NORS HYDR - Elastic Hoop Buckling Strength, fhe
Clause/(Eqn)
Commentary
Message
9.2.4.4. NORS HYDR - Characteristic Hoop Buckling Strength, fh
Clause/(Eqn)
Commentary
Message
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419
BEAMST NORSOK Theory
9.2.4.5. NORS HYDR - Hoop Compressive Unity Check, UCh
Clause/(Eqn)
Commentary
Message
9.2.4.6. NORS HYDR - Combined Tension and Hydrostatic Pressure Unity Check
Clause/(Eqn)
Commentary
Message
Method A (Hydrostatic capped-end axial stress excluded)
Net axial tension condition,
Net axial compression condition,
420
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NORSOK Hydrostatic Member Collapse Checks (NORS HYDR)
Clause/(Eqn)
Commentary
Message
Method B (Hydrostatic capped-end axial stress included)
Tension for σac
9.2.4.7. NORS HYDR - Combined Compression and Hydrostatic Pressure Unity Check
Clause/(Eqn)
Commentary
Message
Method A (Hydrostatic capped-end axial stress excluded)
σa = compression
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421
BEAMST NORSOK Theory
Clause/(Eqn)
Commentary
Message
Design axial compressive strength in the presence of external hydrostatic pressure, fchR
Net axial compression condition,
Method B (Hydrostatic capped-end axial stress included)
422
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NORSOK Joint Strength Checks (NORS JOIN)
Clause/(Eqn)
Commentary
Message
9.3. NORSOK Joint Strength Checks (NORS JOIN)
This section discusses the following topics:
9.3.1. NORS JOIN Overview
9.3.2. API Joint Check Report
9.3.3. NORS JOIN Nomenclature
9.3.4. NORSOK Design Strengths and Unity Checks
9.3.5. NORS JOIN - Interpolated Joints
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423
BEAMST NORSOK Theory
9.3.1. NORS JOIN Overview
The NORS JOIN command requests that a joint strength check be performed to the NORSOK design
recommendations (Ref. 24).
The joints may consist of TUBE elements and/or any other beam types that have been assigned tubular
sections in the structural analysis. Non-tubular elements are ignored.
Joints for post-processing are selected using the JOINt command in BEAMST which specifies the node
numbers at the required joint positions. All joints are assumed to be ‘simple’. Elements may be excluded
from the check by using the SECOndary command. Yield stresses must be specified for both the chord
and brace elements at the joints to be checked.
Joints are automatically classed as T or Y depending on the joint geometry as follows. Note that K joints
must be specified explicitly.
1. The chord member is the member with the greatest outside diameter.
2. If two or more potential chord members have equal outside diameters then BEAMST will consider the
two with the largest wall thickness as the chord members and will check, for each loadcase, the most
highly stressed of these against all other brace members.
3. In the case of more than two potential chord members with equal diameters and wall thicknesses the
first two encountered will be considered as the chord member-as shown in the Cross Check Report.
4. If the CHORd command is used to specify a chord member, this will alone be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being considered.
BEAMST selects ‘simple’ joint (i.e., brace - chord pairs) ‘types’ as follows:
1. Brace members ‘perpendicular’ to the chord members (i.e., smaller included angle greater than or equal
80 degrees) as T joints.
2. Single non-‘perpendicular’ braces are classified as Y joints. (The smaller included angle is less than 80
degrees.)
3. K joints are specified by identifying both braces forming the joint. Note that the NORSOK code assumes
that the axial loads in the braces are balanced for K joint action. Each brace to be checked should be
identified as well as the other brace that carries the balancing load.
4. Cross joints (X) must be specified by the user.
5. In the case of user specified K or X joints no search is performed for a second brace member in the same
brace-chord plane as the first brace.
6. Brace members specified on joint TYPE commands are automatically selected as braces in the above
brace-chord member selection process.
7. No conflict between CHORd command specified members and brace members specified on joint TYPE
commands is permitted.
424
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NORSOK Joint Strength Checks (NORS JOIN)
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHORd commands. Interpolated joint
classification may be defined using the TYPE command. For K joints a gap dimension may be specified
in the TYPE command. A default gap dimension may be specified using the GAPD command.
Two summary reports are available:
Summary report 1 details the loadcase producing the highest unity check for each chord/brace pair at
a joint.
Summary report 3 comprises the highest unity check for each selected loadcase for each chord/brace
pair at a joint.
BEAMST commands applicable to the NORSOK JOIN command are given in Table 9.3: NORSOK JOIN
Commands (p. 425) below and are described in detail in BEAMST Command Reference (p. 51). An example
data file is given in Example 9.3: Example of a NORS JOIN data file (p. 426).
Table 9.3: NORSOK JOIN Commands
Command
Description
Usage
Note
NORS JOIN
NORSOK joint check header command
C
UNIT
Units of length and force
YIEL
Yield stress
MCOF
Partial Material Coefficient
JOIN
Joint numbers to be reported
TYPE
Joint type and brace element definition
CHOR
Chord elements at a joint and associated parameters
SECO
Secondary members to be ignored in checks
DESI
Defines section properties
PROF
Section profiles for use in design
GAPD
Default gap dimension
STUB
Tubular members’ end stub dimensions
CASE
Basic loadcases to be reported
C
2
COMB
Define a combined loadcase for processing
C
2
CMBV
Define a combined loadcase for processing
C
2
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
1
C
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425
BEAMST NORSOK Theory
Command
Description
TITL
Redefine global title
END
Terminates command data block
Usage
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 9.3: Example of a NORS JOIN data file
SYSTEM DATA AREA 200000
TEXT***************************************************************
JOB OLD POST
TEXT VALIDATION OF NORSOK JOINT FACILITY FOR BEAMST
PROJECT N836
STRUCTURE N836
FILES J836
OPTIONS GOON
UNITS KN M
END
NORS ED98 JOIN
PRINT ALL
PRINT UNCK SUM1 SUM3
COMB 2 7.0 1
TEXT
TEXT SET DEFAULT YIELD STRESS FOR ALL GROUPS AND ELEMENTS
TEXT
YIEL 345000.0 GROU ALL
JOIN 752
CHOR 752 745 746
YIEL 340000.0 ELEM 745
YIEL 340000.0 ELEM 746
STUB END2 1.2000 0.0300 ELEM 745
STUB END1 1.2000 0.0300 ELEM 746
STUB END2 1.0000 0.0200 ELEM 751
TEXT
TEXT CHECK BOTH ARMS OF THE K JOINTS
TEXT
TYPE 752 K 751 755 0.0000 ALL
STUB END1 1.0000 0.0200 ELEM 755
TYPE 752 K 755 751 0.0000 ALL
STUB END2 1.0000 0.0200 ELEM 585
TYPE 752 X 585 ALL
STUB END2 1.0000 0.0200 ELEM 586
TYPE 752 X 586 ALL
STUB END1 1.0000 0.0200 ELEM 785
TYPE 752 X 785 ALL
STUB END1 1.0000 0.0200 ELEM 786
TYPE 752 X 786 ALL
JOIN 712
CHOR 712 501 601
YIEL 415000.0 ELEM 501
YIEL 415000.0 ELEM 601
STUB END2 2.0000 0.0400 ELEM 501
STUB END1 2.0000 0.0400 ELEM 601
STUB END1 1.2000 0.0300 ELEM 745
TYPE 712 T 745 ALL
JOIN 785
CHOR 785 743 744
YIEL 340000.0 ELEM 743
YIEL 340000.0 ELEM 744
426
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Note
NORSOK Joint Strength Checks (NORS JOIN)
STUB
STUB
STUB
TYPE
JOIN
CHOR
YIEL
YIEL
STUB
STUB
STUB
TYPE
JOIN
CHOR
YIEL
YIEL
STUB
STUB
STUB
TYPE
END
STOP
END2 1.2000 0.0300
END1 1.2000 0.0300
END2 1.0000 0.0200
785 Y 757 ALL
956
956 962 963
345000.0 ELEM 962
345000.0 ELEM 963
END2 1.0000 0.0200
END1 1.0000 0.0200
END2 1.0000 0.0200
956 X 961 ALL
956
956 962 963
345000.0 ELEM 962
345000.0 ELEM 963
END2 1.0000 0.0200
END1 1.0000 0.0200
END1 1.0000 0.0200
956 X 964 ALL
ELEM 743
ELEM 744
ELEM 757
ELEM 962
ELEM 963
ELEM 961
ELEM 962
ELEM 963
ELEM 964
9.3.2. API Joint Check Report
The detailed JOINT check report provides information on joint geometric parameters, type, acting chord
and brace loading, Qf, and Qu factors, nominal load allowables and unity checks. This may be requested
using the PRINt UNCK command. The maximum unity check is flagged for ease of reference.
Messages displayed in output reports or obtained from the database have the following meanings:
FAIL
Unity check value exceeds unity
PNT9
Unity check value exceeds 0.9
MEMB
Joint utilization exceeds brace utilization assuming that the latter is conservatively taken as unity. More
detail check is required, which is not currently undertaken by the program.
NOCK
No check has been carried out, due to one of the following error messages
BETA
Beta value β is outside the valid API range.1
THET
Theta value θ is outside the valid API range.1
GAMA
Gamma value γ is outside the valid API range.1
NOCY
Computed Py value is less than zero.
1
Error message
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BEAMST NORSOK Theory
DIST
The distance between work points exceeds D/4.2
9.3.3. NORS JOIN Nomenclature
NORS JOIN uses the following nomenclature:
9.3.3.1. NORS JOIN Nomenclature - Dimensional
9.3.3.2. NORS JOIN Nomenclature - Acting Forces and Stresses
9.3.3.3. NORS JOIN Nomenclature - Allowable Forces, Moments, Stresses and Unity Checks
9.3.3.4. NORS JOIN Nomenclature - Parameters
9.3.3.1. NORS JOIN Nomenclature - Dimensional
Lc
Effective chord length (Figure 6-3 of NORSOK)
D
Chord diameter
d
Brace diameter
R
Chord radius
r
Brace radius
T
Chord thickness
Tn
Nominal chord thickness (away from the joint)
t
Brace thickness
γ
Ratio between the chord radius and thickness R/T
2
Warning message
428
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NORSOK Joint Strength Checks (NORS JOIN)
τ
Ratio between the thickness of the brace and chord t/T
θ
Angle between brace and chord
β
Ratio between the diameter of the brace and chord d/D
g
K joint gap
9.3.3.2. NORS JOIN Nomenclature - Acting Forces and Stresses
P
Brace axial force
Mip
Brace in-plane bending moment
Mop
Brace out-of-plane bending moment
σaxc
Chord axial stress component
σipc
Chord in-plane bending stress
σopc
Chord out-of-plane bending stress
σaxb
Brace axial stress component
σipb
Brace in-plane bending stress
σopb
Brace out-of-plane bending stress
fb
Resultant brace bending stress
9.3.3.3. NORS JOIN Nomenclature - Allowable Forces, Moments, Stresses and Unity
Checks
fy
Chord yield stress
fyb
Brace yield stress
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429
BEAMST NORSOK Theory
NRd
Allowable braceaxial force
MRd
Allowable brace moment
Px
Allowable axial force for load transfer across chords
UCax
Axial force unity check
UCip
In-plane bending unity check
UCop
Out-of-plane bending unity check
UCx
Load transfer across chord unity check
UCco
Combined axial and bending unity check
UCjt
Joint strength unity check
9.3.3.4. NORS JOIN Nomenclature - Parameters
γm
Material factor
9.3.4. NORSOK Design Strengths and Unity Checks
This section discusses the following topics:
9.3.4.1. NORS JOIN - Chord Action Factor, Qf
9.3.4.2. NORS JOIN - Strength Factor Qu
9.3.4.3. NORS JOIN - Characteristic Resistances
9.3.4.4. NORS JOIN - Combined Axial and Bending Unity Checks
430
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NORSOK Joint Strength Checks (NORS JOIN)
9.3.4.1. NORS JOIN - Chord Action Factor, Qf
Clause/(Eqn)
Commentary
Message
9.3.4.2. NORS JOIN - Strength Factor Qu
Clause/(Eqn)
Commentary
Message
For K joints
Gap factor
Angle correction factor
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431
BEAMST NORSOK Theory
Clause/(Eqn)
Commentary
Message
Qu is obtained from:
9.3.4.3. NORS JOIN - Characteristic Resistances
Clause/(Eqn)
432
Commentary
Message
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NORSOK Joint Strength Checks (NORS JOIN)
9.3.4.4. NORS JOIN - Combined Axial and Bending Unity Checks
Clause/(Eqn)
Commentary
Message
9.3.5. NORS JOIN - Interpolated Joints
Clause/(Eqn)
Commentary
Message
If an interpolatory joint type classification is specified,
two sets of geometry and loading factors Qu are calculated (Qu1 and Qu2). Two corresponding sets of nominal
load allowables are then computed where each assumes
the joint to be 100% of the respective types. If the joint
is specified as C% joint type 1, the combined unity check
is calculated as:
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433
434
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Chapter 10: BEAMST ISO Theory
The ISO command data block is used to request member allowable, hydraulic collapse and joint
checking to the ISO code of practice (Ref. 27).
10.1. ISO Member Code Check (ISO MEMB)
This section discusses the following topics:
10.1.1. ISO MEMB Overview
10.1.2. ISO Allowable Unity Check Report
10.1.3. ISO MEMB Nomenclature
10.1.4. ISO Design Strengths and Unity Checks
10.1.5. ISO Design Strengths and Unity Checks for Dented Members
10.1.1. ISO MEMB Overview
The ISO MEMB header command in BEAMST is used to request member allowable checks to the ISO
structural design standard (Ref. 27).
The code checks are only available for tubular members, including beam elements that have been assigned circular tubular sections in the structural analysis.
The ISO code of practice is written in terms of material yield strengths, so YIELd commands are necessary
to specify the material strengths of all members that are to be checked. The units of the yield strength
must be those of the UNIT command.
Members may be selected for processing by member or group. Additional commands available for defining the topological characteristics of the members include the EFFE and UNBR commands. Dented
tubular members may be assessed by specifying the DENT command.
The ISO standard utilizes limit state checks with partial resistance factors to achieve the desired level
of safety. In keeping with this principle, applied loads must be multiplied by appropriate partial action
factors, as defined in the code of practice, to develop the design load case combinations necessary for
processing. Where non-linear pile analysis is undertaken (e.g. using SPLINTER) the design loads must
be applied to the pile model to account for the increased non-linearity this introduces. In situations
where a non-linear pile analysis has not been carried out, the design loads may be produced using the
COMB or CMBV commands utilizing the required load factors. For abnormal loading conditions the
ABNO command may be used to set the partial resistance factors to unity.
The SECT command may be used to specify the number of intermediate points along a member at
which member forces and moments are to be evaluated, checked and reported. These are in addition
to the values automatically output at the member ends and any changes of cross-section properties.
For the code checks it is necessary to ensure the maximum acting bending moments and stresses are
evaluated. Since this may not occur at one of the ‘selected’ locations, BEAMST has a SEARch command
which causes the moments and stresses to be evaluated at every L/4 and L/6 (L = beam length) for
prismatic and stepped beams respectively. These extra locations are in addition to those selected and
the results at these locations are only presented if they give the maximum moments or stresses.
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435
BEAMST ISO Theory
The selection of output reports is made using the PRIN command with the appropriate parameters for
the required reports. The PRIN command is also used to request the various summary reports available
and to set exceedence values for the unity checks. Two summary reports are available:
Summary report 1 is requested with the PRIN SUM1 subcommand and gives the highest local buckling,
global buckling and yield unity check values for each requested element.
Summary report 3 is requested with the PRIN SUM3 subcommand and gives the highest unity check
for each loadcase for each selected element.
A list of the commands available for the ISO member code checks is given in Table 10.1: ISO MEMB
Commands (p. 436) below and described in detail in BEAMST Command Reference (p. 51). An example
data file is given in Example 10.1: Example of an ISO MEMB data file (p. 437).
Table 10.1: ISO MEMB Commands
Command
Description
Usage
ISO MEMB
ISO allowable stress header command
C
UNIT
Units of length and force
C
1
YIEL
Yield stress
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
SEAR
Search for maximum forces and stresses
SECO
Secondary members
DESI
Defines design section properties
DENT
Defines dented member properties
PROF
Section profiles for use in design
EFFE
Effective lengths/factors
CMY/CMZ
Amplification reduction factors Cmy/Cmz
UNBR
Unbraced length of element
ULCF
Length of tubular members between stiffening
rings, diaphragms, etc.
ABNO
Abnormal loadcases
CASE
Basic loadcases to be reported
C
3
COMB
Define a combined loadcase for reporting
C
3
CMBV
Define a combined loadcase for reporting
C
3
SELE
Select/redefine a combined/basic loadcase title
436
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Note
ISO Member Code Check (ISO MEMB)
Command
Description
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
Usage
Note
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. At least one CASE, CMBV or COMB command must be included.
Example 10.1: Example of an ISO MEMB data file
SYSTEM DATA AREA 2000000
TITLE Beamst verification test for ISO 19902
t2215be1.dat 23/01/2009
TEXT **************************************************************************
TEXT ISO TEST FOR MEMBERS AND HYDROSTATIC CAPABILITY
t2215be1.dat
TEXT CREATED 23/01/09
TEXT
TEXT ASSOCIATED FILES
TEXT T2215ASA.DAT ASAS ANALYSIS OF SIMPLE JACKET STRUCTURE
TEXT T2215BE1.DAT BEAMST RUN MEMBER CHECK
TEXT T2215BE2.DAT BEAMST RUN HYDRO CHECK (BRIG)
TEXT T2215BE3.DAT BEAMST RUN HYDRO CHECK (NOT BRIG)
TEXT **************************************************************************
JOB OLD POST
PROJECT
T215
STRUCTURE T215
OPTIONS GOON
UNITS STRESS N MM
SAVE FEMU FILES CREATE T2215A FILE T2215A.FVI
END
ISO ED1 MEMB
TEXT
TEXT
Following data generated by OASIS execute module 'pre_beamst', Version 4r3
TEXT
UNITS N
M
TEXT
TEXT - ELEMENTS AND YIELD STRESSES
TEXT
ELEM
501
502
503
504
581
582
583
584
585
586
587
588
:
681
682
683
684
685
686
687
688
741
743
745
747
:
761
762
763
764
TEXT
TEXT - COMBINATIONS
TEXT
SELE
2 basic loading x 1.0
COMB
2
1.000
1
SELE
3 basic loading x 0.7
COMB
3
-0.700
1
SELE
4 basic loading x 1.3
COMB
4
1.300
1
TEXT
TEXT - GEOMETRY
TEXT
AUGM 0
2.0000
0.0200 ELEM
501
YIEL 200000000. ELEM
501
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437
BEAMST ISO Theory
AUGM 1
2.5000
2.1000
0.0250
0.0200
GEOM
0.13960000
0.50000000E-01 0.90500000E-01 0.22550833E-04
:
0.30727053E-01 0.16124172
ELEM
502
YIEL 200000000. ELEM
502
YIEL 200000000. ELEM
504
AUGM 0
1.0000
0.0200 ELEM
581
YIEL 200000000. ELEM
581
AUGM 0
1.0000
0.0600 ELEM
582
YIEL 200000000. ELEM
582
AUGM 3
1.1000
0.9000
0.0150
0.0250
GEOM
0.80500000E-01 0.55000000E-01 0.27000000E-01 0.17719126E-01
:
0.12065521E-01 0.13051121E-01 ELEM
583
YIEL 200000000. ELEM
583
YIEL 200000000. ELEM
584
AUGM 0
1.0000
0.0200 ELEM
585
YIEL 200000000. ELEM
585
AUGM 1
3.5000
1.1000
0.0300
0.0250
GEOM
0.14162500
0.87500000E-01 0.55500000E-01 0.32530208E-04
:
0.48507357E-02 0.25017080
ELEM
586
YIEL 200000000. ELEM
586
AUGM 0
1.0000
0.0200 ELEM
587
YIEL 200000000. ELEM
587
AUGM 1
3.5000
1.1000
0.0300
0.0250
GEOM
0.14162500
0.87500000E-01 0.55500000E-01 0.32530208E-04
:
0.48507357E-02 0.25017080
ELEM
588
YIEL 200000000. ELEM
588
AUGM 0
1.0000
0.0200 ELEM
681
YIEL 450000000. ELEM
681
AUGM 0
1.0000
0.0200 ELEM
682
YIEL 200000000. ELEM
682
AUGM 0
1.0000
0.0200 ELEM
683
YIEL 200000000. ELEM
683
AUGM 0
1.0000
0.0150 ELEM
685
YIEL 200000000. ELEM
685
YIEL 200000000. ELEM
686
AUGM 0
0.3000
0.0120 STEP
1 ELEM
741
YIEL 200000000. STEP
1 ELEM
741
AUGM 0
0.4000
0.0120 STEP
2 ELEM
741
YIEL 200000000. STEP
2 ELEM
741
AUGM 0
0.5000
0.0120 STEP
3 ELEM
741
YIEL 200000000. STEP
3 ELEM
741
AUGM 0
0.4000
0.0120 STEP
4 ELEM
741
YIEL 200000000. STEP
4 ELEM
741
AUGM 0
0.3000
0.0120 STEP
5 ELEM
741
YIEL 200000000. STEP
5 ELEM
741
YIEL 200000000. ELEM
743
AUGM 0
0.3000
0.0120 STEP
1 ELEM
745
YIEL 200000000. STEP
1 ELEM
745
AUGM 0
0.4000
0.0120 STEP
2 ELEM
745
YIEL 200000000. STEP
2 ELEM
745
AUGM 0
0.5000
0.0120 STEP
3 ELEM
745
YIEL 200000000. STEP
3 ELEM
745
AUGM 0
0.4000
0.0120 STEP
4 ELEM
745
YIEL 200000000. STEP
4 ELEM
745
AUGM 0
0.3000
0.0120 STEP
5 ELEM
745
YIEL 200000000. STEP
5 ELEM
745
YIEL 200000000. ELEM
762
AUGM 3
1.1500
0.8500
0.0180
0.0100
GEOM
0.52880000E-01 0.23000000E-01 0.30600000E-01 0.11311586E-01
:
0.57727527E-02 0.12107836E-01 ELEM
763
YIEL 200000000. ELEM
763
AUGM 0
1.0000
0.0200 ELEM
764
YIEL 200000000. ELEM
764
TEXT
TEXT - SECTIONS
TEXT
SECT
0.001
0.500
0.999
ELEM
501
SECT
0.001
0.500
0.999
ELEM
502
SECT
0.001
0.500
0.999
ELEM
504
SECT
0.001
0.300
0.500
0.700
0.900
ELEM
581
SECT
0.001
0.500
0.999
ELEM
582
SECT
0.001
0.500
0.999
ELEM
583
438
ELEM
502
ELEM
583
ELEM
586
ELEM
588
ELEM
763
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ISO Member Code Check (ISO MEMB)
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.300
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.000
0.069
SECT
0.889
ELEM
741
SECT
0.001
0.500
SECT
0.029
0.100
SECT
0.943
ELEM
745
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
TEXT
TEXT - STRESS FACTOR
TEXT
TEXT
TEXT - PARAMETERS
TEXT
CMY
0.850 ELEM
501
CMZ
0.850 ELEM
501
EFFE
1.000
1.000
UNBR
30.000
30.000
CMY
0.850 ELEM
502
CMZ
0.850 ELEM
502
EFFE
1.000
1.000
UNBR
30.000
30.000
CMY
0.850 ELEM
503
CMZ
0.850 ELEM
503
EFFE
1.000
1.000
UNBR
0.000
0.000
CMY
0.850 ELEM
504
CMZ
0.850 ELEM
504
EFFE
1.000
1.000
UNBR
30.000
30.000
CMY
0.850 ELEM
581
CMZ
0.850 ELEM
581
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
582
CMZ
0.850 ELEM
582
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
583
CMZ
0.850 ELEM
583
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
584
CMZ
0.850 ELEM
584
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
585
CMZ
0.850 ELEM
585
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
586
CMZ
0.850 ELEM
586
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
587
CMZ
0.850 ELEM
587
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
588
CMZ
0.850 ELEM
588
EFFE
1.000
1.000
UNBR
23.049
23.049
0.999
0.999
0.999
0.999
0.999
0.500
0.999
0.999
0.999
0.999
0.264
ELEM
584
ELEM
585
ELEM
586
ELEM
587
ELEM
588
0.700
0.900
ELEM
682
ELEM
683
ELEM
685
ELEM
686
0.458
0.652
0.999
0.300
ELEM
743
0.500
0.699
0.999
0.999
0.999
ELEM
ELEM
ELEM
ELEM
ELEM
501
501
ELEM
ELEM
502
502
ELEM
ELEM
503
503
ELEM
ELEM
504
504
ELEM
ELEM
581
581
ELEM
ELEM
582
582
ELEM
ELEM
583
583
ELEM
ELEM
584
584
ELEM
ELEM
585
585
ELEM
ELEM
586
586
ELEM
ELEM
587
587
ELEM
ELEM
588
588
ELEM
681
0.847
ELEM
741
0.900
ELEM
745
762
763
764
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439
BEAMST ISO Theory
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
32.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
35.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
35.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
24.749
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
24.749
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
24.749
PRINT UNCK SUM1 SUM3
END
STOP
440
681
681
1.000
23.049
682
682
1.000
23.049
683
683
1.000
23.049
684
684
1.000
0.000
685
685
1.000
23.049
686
686
1.000
23.049
687
687
1.000
0.000
688
688
1.000
0.000
741
741
1.000
32.000
743
743
1.000
35.000
745
745
1.000
35.000
747
747
1.000
0.000
761
761
1.000
0.000
762
762
1.000
24.749
763
763
1.000
24.749
764
764
1.000
24.749
ELEM
ELEM
681
681
ELEM
ELEM
682
682
ELEM
ELEM
683
683
ELEM
ELEM
684
684
ELEM
ELEM
685
685
ELEM
ELEM
686
686
ELEM
ELEM
687
687
ELEM
ELEM
688
688
ELEM
ELEM
741
741
ELEM
ELEM
743
743
ELEM
ELEM
745
745
ELEM
ELEM
747
747
ELEM
ELEM
761
761
ELEM
ELEM
762
762
ELEM
ELEM
763
763
ELEM
ELEM
764
764
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ISO Member Code Check (ISO MEMB)
10.1.2. ISO Allowable Unity Check Report
The unity check report is presented on an element by element basis. The header line displays the element
number, the associated node numbers, the element group number and the units in use. The results are
printed for each of the selected positions (or sections) on the element for each loadcase in turn. The
first columns of the report define the loadcase, section number and position as a ratio of the elements
length together with the section diameter and thickness, slenderness ratios and the column slenderness
parameter (λ).
The next two columns present the acting axial, shear and bending stresses pertaining to the given
loadcase.
The allowable stresses for axial, shear and bending (in local Y and Z axes) stresses are presented in the
next columns of the report together with the Euler buckling strengths (Fey and Fez), the reduced yield
stress for local and column buckling interaction and the inelastic buckling strength. These are preceded
by an alpha- numeric descriptor (CODE) that indicates the derivation of each of the main allowable
stresses. These descriptors are of the form:
T.XVYZ or C.XVYZ
T or C defines whether the member is in tension or compression, XVYZ are individual alpha codes which
relate to the axial(X), shear(V), and bending(Y,Z) allowable stresses. These alpha codes specify the design
code clause or equation used to evaluate the allowable stresses and are defined in Table 10.2: ISO MEMB
Allowable Stress Alphabetic Codes (p. 441).
Table 10.2: ISO MEMB Allowable Stress Alphabetic Codes
Stress
Code Clause
Description
X
A
axial tension
C
(13.2-5)
E
(13.2-6)
V
Y
(13.2-17)
Y
C
(13.2-13)
axial/compression axial/compression shear yield
bending Z
G
(13.2-14)
bending -
H
(13.2-15)
bending -
For example, the unity check CODE combination
C.CYCC
indicates that the member is in compression and that the following clause/equations were used to derive
the allowable stresses:
• Axial - C = (13.2-5) axial compression -
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• Shear - Y = (13.2-17) shear yield
• Bending - C = (13.2-13) bending The last two characters are always the same for tubular members.
The final columns of the table, headed Messages, flag all lines of results where any of the checks have
failed. These messages may be summarized as follows:
FAIL
Member has a utilization exceeding unity or fails parameter limits (flagged with THKF, DTRF, YIEL, DENF
or SHYF)
PNT9
Unity check value exceeds 0.9
THKF
Wall thickness less than 6mm
DTRF
Allowed diameter thickness ratio exceeded
YIEL
Yield stress greater than 500MPa
DENF
Dent depth exceeds limits
SHYF
Shear yielding failure
10.1.3. ISO MEMB Nomenclature
ISO MEMB uses the following nomenclature:
10.1.3.1. ISO MEMB Nomenclature - Dimensional
10.1.3.2. ISO MEMB Nomenclature - Acting Section Stresses
10.1.3.3. ISO MEMB Nomenclature - Design Strengths and Unity Checks
10.1.3.4. ISO MEMB Nomenclature - Parameters
442
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ISO Member Code Check (ISO MEMB)
10.1.3.1. ISO MEMB Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
k
Effective length factor (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
L
Unbraced length of member (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
i
Radius of gyration (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
A
Cross sectional area
I
Bending inertia
Ip
Polar moment of inertia
W
Elastic section modulus
Z
Plastic section modulus
h
Dent depth
Quantities last subscripted with d are related to damaged members.
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10.1.3.2. ISO MEMB Nomenclature - Acting Section Stresses
fa
Axial stress
fby, fbz
Bending stresses about y and z
fv
Maximum shear stress
fvt
Torsional shear stress
Quantities last subscripted with d are related to damaged members.
10.1.3.3. ISO MEMB Nomenclature - Design Strengths and Unity Checks
fy
Yield stress
Fey, Fez
Euler buckling resistance for y and z axes (minimum if no y or z subscript)
fcle
Characteristic elastic local buckling strength
fcl
Characteristic local buckling strength
fc
Column axial compressive strength
fm
Characteristic bending strength
Ft
Design tension strength
Fc
Design compressive strength
Fb
Design bending strength
Fc
Design beam shear strength
Fv
Design torsion shear strength
444
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ISO Member Code Check (ISO MEMB)
Fcl
Design axial local buckling resistance
UCax
Axial unity check
UCvmax
Flexural shear unity check
UCTOR
Torsional shear unity check
UCby
Pure bending check about y axis
UCbz
Pure bending check about z axis
UCbr
Pure resultant bending check
UCy1
Combined axial tension and bending check (for tension)
UCy1
Combined axial compressions and bending yield unity check 1 (for compression)
UCy2
Combined axial compression and bending yield unity check 2
Quantities last subscripted with d are related to damaged members.
10.1.3.4. ISO MEMB Nomenclature - Parameters
E
Young's modulus
Cmy, Cmz
Moment amplification reduction factors
Column slenderness parameter (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
γt
Partial resistance factor for axial tensile strength
γc
Partial resistance factor for axial compressive strength
γv
Partial resistance factor for shear strength
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γb
Partial resistance factor for bending strength
Quantities last subscripted with d are related to damaged members.
10.1.4. ISO Design Strengths and Unity Checks
This section discusses the following topics:
10.1.4.1. Design Tension Strength, Ft
10.1.4.2. Design Compression Strength, Fc
10.1.4.3. Design Bending Strength, Fb
10.1.4.4. Design Shear Strengths, Fv and Fve
10.1.4.5. ISO MEMB - Unity Checks
10.1.4.6. ISO MEMB - Combined Forces
10.1.4.1. Design Tension Strength, Ft
Clause/(Eqn)
Commentary
Code Message
Design Strength
(13.2-1)
Where γt = 1.05
10.1.4.2. Design Compression Strength, Fc
Clause/(Eqn)
Commentary
13.1
If
.............................................
Code Message
DTRF
THKF
If t < 6mm .............................................
Characteristic elastic local buckling strength, fcle
(13.2-10)
Characteristic local buckling strength, fcl
(13.2-8)
SHEL
If
(13.2-9)
then
446
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ISO Member Code Check (ISO MEMB)
Clause/(Eqn)
Commentary
Code Message
else
Column slenderness parameter,
(13.2-7)
Column axial compressive strength, fc
If
(13.2-5)
then
(13.2-6)
else
(13.2-3)
Where γc = 1.18
10.1.4.3. Design Bending Strength, Fb
Clause/(Eqn)
Commentary
Code Message
Characteristic bending strength, fm
If
(13.2-13)
then
If
then
(13.2-14)
If
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Clause/(Eqn)
Commentary
Code Message
then
(13.2-15)
(13.2-11)
Where γb = 1.05
10.1.4.4. Design Shear Strengths, Fv and Fve
Clause/(Eqn)
Commentary
Code Message
Beam Shear
(13.2-16)
γv = 1.05
Torsional Shear
(13.2-18)
10.1.4.5. ISO MEMB - Unity Checks
Clause/(Eqn)
Commentary
Code Message
Axial
(13.2-4)
fa compressive
(13.2-2)
fa tensile
Shear
(13.2-17)
448
SHYF
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ISO Member Code Check (ISO MEMB)
Clause/(Eqn)
Commentary
Code Message
If UCvmax > 1.0 .............................................
(13.2-19)
Pure Bending
(13.2-12)
10.1.4.6. ISO MEMB - Combined Forces
Clause/(Eqn)
Commentary
Code Message
Axial tension and bending
(13.3-1)
UCy2 = 0.0
Axial compression and bending
(13.3-7)
(13.3-8)
Design axial local buckling resistance, Fcl
UCy2 = 0.0
Euler buckling strengths, Fey, Fez
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449
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Clause/(Eqn)
Commentary
Code Message
(13.3-9)
(13.3-6)
10.1.5. ISO Design Strengths and Unity Checks for Dented Members
This section discusses the following topics:
10.1.5.1. Dent Parameters
10.1.5.2. Design Tension Strength, Ftd, for Dented Members
10.1.5.3. Design Compression Strength, Fcd, for Dented Members
10.1.5.4. Design Bending Strength, Fbd, for Dented Members
10.1.5.5. Design Shear Strengths, Fvd and Fved, for Dented Members
10.1.5.6. ISO MEMB - Unity Checks for Dented Members
10.1.5.7. ISO MEMB - Combined Forces for Dented Members
10.1.5.1. Dent Parameters
Clause/(Eqn)
(13.7-1)
Commentary
If
If
.............................................
Code Message
DENF
.............................................
DENF
Effective cross-sectional area, Ad
Effective moment of area, Id
Radius of gyration of dented member, id
450
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ISO Member Code Check (ISO MEMB)
10.1.5.2. Design Tension Strength, Ftd, for Dented Members
Clause/(Eqn)
Commentary
Code Message
Design Strength
(13.7-1)
Where γtd = 1.05
10.1.5.3. Design Compression Strength, Fcd, for Dented Members
Clause/(Eqn)
Commentary
13.1
If
.............................................
Code Message
DTRF
THKF
If t < 6mm .............................................
Characteristic elastic local buckling strength, fcle
(13.2-10)
Characteristic local buckling strength, fcl
If
(13.2-8)
then
SHEL
(13.2-9)
else
Column slenderness parameter,
(13.7-10)
Column axial compressive strength, fcdo
If
(13.7-7)
then
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Clause/(Eqn)
Commentary
Code Message
else
(13.7-8)
(13.7-5)
If
fcd = fcdo
(13.7-6)
else
Euler buckling strength of dented member, fed
(13.7-3)
Where γcd = 1.18
10.1.5.4. Design Bending Strength, Fbd, for Dented Members
Clause/(Eqn)
Commentary
Code Message
Characteristic bending strength, fm
(13.2-13)
(13.2-14)
If
then
If
(13.2-15)
then
(13.7-16)
If
452
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ISO Member Code Check (ISO MEMB)
Clause/(Eqn)
Commentary
(13.7-18)
then
(13.7-20)
For +ve bending (I.e stress at dent is tensile)
Code Message
Where γb = 1.05
For -ve bending (I.e stress at dent is compressive)
For neutral bending
10.1.5.5. Design Shear Strengths, Fvd and Fved, for Dented Members
Clause/(Eqn)
Commentary
Code Message
Beam Shear
(13.2-16)
γvd = 1.05
Torsional Shear
(13.2-18)
10.1.5.6. ISO MEMB - Unity Checks for Dented Members
Clause/(Eqn)
Commentary
Code Message
Axial
fa compressive
(13.7-2)
fa tensile
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453
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Clause/(Eqn)
Commentary
(13.7-4)
Shear
Code Message
(13.7-17)
SHYF
(13.7-22)
(13.7-23)
If UCvmax > 1.0 .............................................
(13.7-19)
Pure Bending
Assuming dent on Y-axis
(13.7-17)
(13.7-19)
(13.7-21)
(13.7-27)
10.1.5.7. ISO MEMB - Combined Forces for Dented Members
Clause/(Eqn)
Commentary
Code Message
Assuming dent on Y-axis Axial tension, +ve bending and
neutral bending
454
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ISO Member Code Check (ISO MEMB)
Clause/(Eqn)
Commentary
Code Message
(13.7-25)
UCy2 = 0.0
Axial tension, -ve bending and neutral bending
(13.7-26)
UCy2 = 0.0
(13.7-27)
Axial compression, +ve bending and neutral bending
(13.7-32)
(13.7-33)
Design axial local buckling resistance of the dented
member, Fcld
Euler buckling strengths of undamaged member, Fey,
Fez
(13.3-5)
(13.3-6)
Fe = min (Fey,Fez)
Axial compression, +ve bending and neutral bending
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455
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Clause/(Eqn)
Commentary
Code Message
(13.7-34)
(13.7-35)
10.2. ISO Hydrostatic Member Collapse Checks (ISO HYDR)
This section discusses the following topics:
10.2.1. ISO HYDR Overview
10.2.2. ISO Hydrostatic Unity Check Reports
10.2.3. ISO HYDR Nomenclature
10.2.4. ISO Unity Checks
10.2.1. ISO HYDR Overview
The ISO HYDR header command is used to request that hydrostatic pressure, allowable stresses, member
actions, unity checks and combined stress hydrostatic collapse unity checks be performed according
to the ISO design recommendations (Ref. 27). This check is implemented in BEAMST for tubular elements,
or other element types that have been assigned tubular sections in the structural analysis.
Members may be selected for processing by element and/or group. The member section dimensions
may be redefined using the DESI commands to modify the diameter and/or the thickness. Further
commands are available for defining topological characteristics of the members (EFFE, UNBR and ULCF)
and specifying members that are classified as secondary (SECO).
The SECT command may be used to define intermediate points along an element at which member
forces and moments are to be evaluated, checked and reported. These are in addition to the results
automatically printed at member end points and any positions of step-change of cross-section along
the member. Alternatively the SEARch command may be used which requests that moments and stresses
are to be evaluated at specified locations along the beam, but only reported if they give a maximum
force, stress or utilization. These locations are in addition to those selected using the SECT command.
The ISO code of practice allows hydrostatically induced stresses to be considered in alternate ways. In
“Method A” the stresses due to end-cap forces are presumed to be excluded from the raw element
forces. Conversely in “Method B” the stresses due to end-cap forces are presumed to be included.
Both of these methods are implemented in BEAMST. The user should select the appropriate method
for the member force and moment data that are being supplied to BEAMST. If the user had requested
“rigorous buoyancy” to be included in a previous ASAS-WAVE analysis, by using the option BRIG on the
OPTIONS data line, then Method B is appropriate. This should be selected by either specifying the BRIG
option in BEAMST or by including a BRIG command in the command deck for BEAMST. Conversely, if
the user did not specify BRIG in the preceding ASAS-WAVE analysis then the BRIG option should be
omitted from the BEAMST options. The inclusion of a BRIG OFF command has the same effect. By default
the end-cap forces are assumed to be excluded from the analysis, i.e., BRIG is OFF unless specifically
456
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
requested. In ASAS-WAVE the BRIG option calculates the member axial forces due to hydrostatic effects.
These are then passed to ASAS through the generated wave load data.
The calculation of hydrostatic pressure requires a knowledge of the position of each member with respect
to still water level, tide height, wave height and length as well as details of the sea medium. Various
commands are available in BEAMST to define these data. First a reference frame must be specified for
the (sea) water axes and its origin in terms of the jacket reference frame defined (i.e., the global co-ordinate system used in the preceding ASAS analysis) using a MOVE command. See BEAMST Command
Reference (p. 51) and Ref. 14 for more details. This command is optional and if omitted the wave and
jacket axes are presumed to coincide. Having defined the water axes origin, the relative orientations of
the water and jacket axes must follow. For example the jacket axes may be inclined to the water axes
if the jacket is being analyzed in a semi-submerged position. In order to convert pressure heads to hydrostatic pressure the acceleration due to gravity in the vertical downwards (-Zwater) direction is required.
If the components of the acceleration due to gravity are specified in terms of the jacket axes the water
- jacket axes may be specified in one operation.
The GRAVity command in BEAMST is available for this purpose and is compulsory for the ISO hydrostatic
collapse check. The jacket and water axes are now fixed spatially and the only remaining information
required for calculating the static head is that of the mean sea water level, sea bed level, water density
and tide height. These data are supplied on the compulsory ELEV command. Finally a WAVE command
may be issued to specify the wave height and period which enables prediction of the wave-induced
pressure components. This command is optional. If it is omitted then still water conditions are assumed.
For the calculation of the hydrostatic head the API recommendations are used to obtain the wave
length: this is calculated automatically by BEAMST on the basis of the water depth and wave period
using linear wave theory. Details of this procedure are given in API Allowable Stresses and Unity
Checks (p. 226).
All elements selected for hydrostatic collapse post-processing are assumed to be unflooded and unstiffened (i.e. the axial length of the cylinder between stiffening rings, diaphragms or end connections
is equal to the element length). The unstiffened length may be defined explicitly using the ULCF command. This command allows ring-stiffened tubulars to be checked for hydrostatic collapse between the
stiffening rings. The ISO hydrostatic code checks include some of the basic member interaction checks
and use is made of the unbraced length (UNBR) and effective length parameters (EFFE) together with
the amplification reduction factors Cmy and Cmz. It is, therefore, important that these terms are supplied
in a form consistent with an ISO MEMB check.
The ISO standard utilizes limit state checks with partial resistance factors to achieve the desired level
of safety. In keeping with this principle, applied loads must be multiplied by appropriate partial action
factors, as defined in the code of practice, to develop the design load case combinations necessary for
processing. Where nonlinear pile analysis is undertaken (e.g. using SPLINTER) the design loads must be
applied to the pile model to account for the increased nonlinearity this introduces. In situations where
a non-linear pile analysis has not been carried out, the design loads may be produced using the COMB
or CMBV commands utilizing the required load factors. For abnormal loading conditions the ABNO
command may be used to set the partial resistance factors to unity.
A detailed Unity Check Report incorporating beam section hydrostatic depth, member acting and allowable forces and stresses, membrane hoop and tension or compression collapse interaction unity checks
is available and may be printed using the PRIN UNCK command.
A summary report is also available.
Summary report number 1 is requested using the PRIN SUM1 command and gives the highest unity
check values for each element.
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457
BEAMST ISO Theory
The BEAMST commands applicable to the ISO HYDR collapse command data are given in Table 10.3: ISO
HYDR Commands (p. 458) below and are described in detail in BEAMST Command Reference (p. 51). An
example data file is given in Example 10.2: Example of an ISO HYDR data file (p. 459).
Table 10.3: ISO HYDR Commands
Command
Description
Usage
ISO HYDR
ISO hydrostatic collapse header command
C
UNIT
Units of length and force
Note
1
C
YIEL
Yield stress
ELEV
Water depth and density
MOVE
Water axis origin in global structure axis system
WAVE
Wave height and period
GRAV
Gravitational acceleration relative to structure axis system
BRIG
Selects rigorous buoyancy method for calculation
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
DESI
Defines design section properties
PROF
Section profiles for use in design
ULCF
Length of tubular members between stiffening rings, diaphragms, etc
ABNO
Abnormal loadcases
CASE
Loadcases to be reported
C
3
COMB
Define a combined loadcase for reporting
C
3
CMBV
Define a combined loadcase for reporting
C
3
HYDR
Load factors for design hydrostatic load
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a basic loadcase
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
C
C
Usage
458
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. At least one CASE, CMBV or COMB command must be included.
Example 10.2: Example of an ISO HYDR data file
SYSTEM DATA AREA 2000000
TITLE Beamst verification test for ISO 19902
t2215be2.dat 23/01/2009
TEXT **************************************************************************
TEXT ISO TEST FOR MEMBERS AND HYDROSTATIC CAPABILITY
t2215be2.dat
TEXT CREATED 23/01/09
TEXT
TEXT ASSOCIATED FILES
TEXT T2215ASA.DAT ASAS ANALYSIS OF SIMPLE JACKET STRUCTURE
TEXT T2215BE1.DAT BEAMST RUN MEMBER CHECK
TEXT T2215BE2.DAT BEAMST RUN HYDRO CHECK (BRIG)
TEXT T2215BE3.DAT BEAMST RUN HYDRO CHECK (NOT BRIG)
TEXT **************************************************************************
JOB OLD POST
PROJECT
T215
STRUCTURE T215
OPTIONS GOON NOBL BRIG
SAVE FEMU FILES CREATE T2215B FILE T2215B.FVI
END
ISO ED1 HYDR
MOVE
0.0
0.0
100.0
GRAV
0.0
0.0
-9.807
ELEV
30.0 0.0
1024.0
WAVE
1.0
10.0
hydr
1.1
case 4
TEXT
TEXT Following data generated by OASIS execute module 'pre_beamst', Version 4r3
TEXT
UNITS N
M
TEXT
TEXT - ELEMENTS AND YIELD STRESSES
TEXT
ELEM
501
502
503
504
581
582
583
584
585
586
587
588
:
681
682
683
684
685
686
687
688
741
743
745
747
:
761
762
763
764
TEXT
TEXT - COMBINATIONS
TEXT
SELE
2 basic loading x 1.0
COMB
2
1.000
1
SELE
3 basic loading x 0.7
COMB
3
-0.700
1
SELE
4 basic loading x 1.3
COMB
4
1.300
1
TEXT
TEXT - GEOMETRY
TEXT
AUGM 0
2.0000
0.0200 ELEM
501
YIEL 200000000. ELEM
501
AUGM 1
2.5000
2.1000
0.0250
0.0200 ELEM
502
GEOM
0.13960000
0.50000000E-01 0.90500000E-01 0.22550833E-04
:
0.30727053E-01 0.16124172
ELEM
502
YIEL 200000000. ELEM
502
YIEL 200000000. ELEM
504
AUGM 0
1.0000
0.0200 ELEM
581
YIEL 200000000. ELEM
581
AUGM 0
1.0000
0.0600 ELEM
582
YIEL 200000000. ELEM
582
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459
BEAMST ISO Theory
AUGM 3
1.1000
0.9000
0.0150
0.0250 ELEM
GEOM
0.80500000E-01 0.55000000E-01 0.27000000E-01 0.17719126E-01
:
0.12065521E-01 0.13051121E-01 ELEM
583
YIEL 200000000. ELEM
583
YIEL 200000000. ELEM
584
AUGM 0
1.0000
0.0200 ELEM
585
YIEL 200000000. ELEM
585
AUGM 1
3.5000
1.1000
0.0300
0.0250 ELEM
GEOM
0.14162500
0.87500000E-01 0.55500000E-01 0.32530208E-04
:
0.48507357E-02 0.25017080
ELEM
586
YIEL 200000000. ELEM
586
AUGM 0
1.0000
0.0200 ELEM
587
YIEL 200000000. ELEM
587
AUGM 1
3.5000
1.1000
0.0300
0.0250 ELEM
GEOM
0.14162500
0.87500000E-01 0.55500000E-01 0.32530208E-04
:
0.48507357E-02 0.25017080
ELEM
588
YIEL 200000000. ELEM
588
AUGM 0
1.0000
0.0200 ELEM
681
YIEL 450000000. ELEM
681
AUGM 0
1.0000
0.0200 ELEM
682
YIEL 200000000. ELEM
682
AUGM 0
1.0000
0.0200 ELEM
683
YIEL 200000000. ELEM
683
AUGM 0
1.0000
0.0150 ELEM
685
YIEL 200000000. ELEM
685
YIEL 200000000. ELEM
686
AUGM 0
0.3000
0.0120 STEP
1 ELEM
741
YIEL 200000000. STEP
1 ELEM
741
AUGM 0
0.4000
0.0120 STEP
2 ELEM
741
YIEL 200000000. STEP
2 ELEM
741
AUGM 0
0.5000
0.0120 STEP
3 ELEM
741
YIEL 200000000. STEP
3 ELEM
741
AUGM 0
0.4000
0.0120 STEP
4 ELEM
741
YIEL 200000000. STEP
4 ELEM
741
AUGM 0
0.3000
0.0120 STEP
5 ELEM
741
YIEL 200000000. STEP
5 ELEM
741
YIEL 200000000. ELEM
743
AUGM 0
0.3000
0.0120 STEP
1 ELEM
745
YIEL 200000000. STEP
1 ELEM
745
AUGM 0
0.4000
0.0120 STEP
2 ELEM
745
YIEL 200000000. STEP
2 ELEM
745
AUGM 0
0.5000
0.0120 STEP
3 ELEM
745
YIEL 200000000. STEP
3 ELEM
745
AUGM 0
0.4000
0.0120 STEP
4 ELEM
745
YIEL 200000000. STEP
4 ELEM
745
AUGM 0
0.3000
0.0120 STEP
5 ELEM
745
YIEL 200000000. STEP
5 ELEM
745
YIEL 200000000. ELEM
762
AUGM 3
1.1500
0.8500
0.0180
0.0100 ELEM
GEOM
0.52880000E-01 0.23000000E-01 0.30600000E-01 0.11311586E-01
:
0.57727527E-02 0.12107836E-01 ELEM
763
YIEL 200000000. ELEM
763
AUGM 0
1.0000
0.0200 ELEM
764
YIEL 200000000. ELEM
764
TEXT
TEXT - SECTIONS
TEXT
SECT
0.001
0.500
0.999
ELEM
501
SECT
0.001
0.500
0.999
ELEM
502
SECT
0.001
0.500
0.999
ELEM
504
SECT
0.001
0.300
0.500
0.700
0.900
ELEM
581
SECT
0.001
0.500
0.999
ELEM
582
SECT
0.001
0.500
0.999
ELEM
583
SECT
0.001
0.500
0.999
ELEM
584
SECT
0.001
0.500
0.999
ELEM
585
SECT
0.001
0.500
0.999
ELEM
586
SECT
0.001
0.500
0.999
ELEM
587
SECT
0.001
0.500
0.999
ELEM
588
SECT
0.001
0.300
0.500
0.700
0.900
ELEM
681
SECT
0.001
0.500
0.999
ELEM
682
SECT
0.001
0.500
0.999
ELEM
683
SECT
0.001
0.500
0.999
ELEM
685
460
583
586
588
763
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
SECT
0.001
0.500
SECT
0.000
0.069
SECT
0.889
ELEM
741
SECT
0.001
0.500
SECT
0.029
0.100
SECT
0.943
ELEM
745
SECT
0.001
0.500
SECT
0.001
0.500
SECT
0.001
0.500
TEXT
TEXT - STRESS FACTOR
TEXT
TEXT
TEXT - PARAMETERS
TEXT
CMY
0.850 ELEM
501
CMZ
0.850 ELEM
501
EFFE
1.000
1.000
UNBR
30.000
30.000
CMY
0.850 ELEM
502
CMZ
0.850 ELEM
502
EFFE
1.000
1.000
UNBR
30.000
30.000
CMY
0.850 ELEM
503
CMZ
0.850 ELEM
503
EFFE
1.000
1.000
UNBR
0.000
0.000
CMY
0.850 ELEM
504
CMZ
0.850 ELEM
504
EFFE
1.000
1.000
UNBR
30.000
30.000
CMY
0.850 ELEM
581
CMZ
0.850 ELEM
581
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
582
CMZ
0.850 ELEM
582
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
583
CMZ
0.850 ELEM
583
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
584
CMZ
0.850 ELEM
584
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
585
CMZ
0.850 ELEM
585
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
586
CMZ
0.850 ELEM
586
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
587
CMZ
0.850 ELEM
587
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
588
CMZ
0.850 ELEM
588
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
681
CMZ
0.850 ELEM
681
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
682
CMZ
0.850 ELEM
682
EFFE
1.000
1.000
UNBR
23.049
23.049
CMY
0.850 ELEM
683
0.999
0.264
ELEM
686
0.458
0.652
0.847
ELEM
741
0.999
0.300
ELEM
743
0.500
0.699
0.900
ELEM
745
0.999
0.999
0.999
ELEM
ELEM
ELEM
ELEM
ELEM
501
501
ELEM
ELEM
502
502
ELEM
ELEM
503
503
ELEM
ELEM
504
504
ELEM
ELEM
581
581
ELEM
ELEM
582
582
ELEM
ELEM
583
583
ELEM
ELEM
584
584
ELEM
ELEM
585
585
ELEM
ELEM
586
586
ELEM
ELEM
587
587
ELEM
ELEM
588
588
ELEM
ELEM
681
681
ELEM
ELEM
682
682
762
763
764
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461
BEAMST ISO Theory
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
23.049
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
32.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
35.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
35.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
0.000
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
24.749
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
24.749
CMY
0.850 ELEM
CMZ
0.850 ELEM
EFFE
1.000
UNBR
24.749
PRINT UNCK SUM1 SUNI N
END
STOP
683
1.000
23.049
684
684
1.000
0.000
685
685
1.000
23.049
686
686
1.000
23.049
687
687
1.000
0.000
688
688
1.000
0.000
741
741
1.000
32.000
743
743
1.000
35.000
745
745
1.000
35.000
747
747
1.000
0.000
761
761
1.000
0.000
762
762
1.000
24.749
763
763
1.000
24.749
764
764
1.000
24.749
MM
ELEM
ELEM
683
683
ELEM
ELEM
684
684
ELEM
ELEM
685
685
ELEM
ELEM
686
686
ELEM
ELEM
687
687
ELEM
ELEM
688
688
ELEM
ELEM
741
741
ELEM
ELEM
743
743
ELEM
ELEM
745
745
ELEM
ELEM
747
747
ELEM
ELEM
761
761
ELEM
ELEM
762
762
ELEM
ELEM
763
763
ELEM
ELEM
764
764
10.2.2. ISO Hydrostatic Unity Check Reports
A detailed Unity Check Report may be requested using the PRIN UNCK command. This prints out information such as beam section hydrostatic depth, member acting and allowable forces and stresses,
membrane hoop and tension or compression collapse interaction unit checks. The final column of each
report is reserved for messages. These may be summarized as follows:
FAIL
Code check failure for this member
462
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
Unity check 1.0 or THKF, YIEL, DTRF
PNT9
Unity check value exceeds 0.9
DTRF
Allowed diameter thickness ratio exceeded (D/t >= 300)
THXF
Wall thickness less than recommended minimum of 6mm
YIEL
Yield strength greater than 500MPa
MGTR
Geometry parameter, used in the elastic hoop buckling stress, µ, greater than 1.6 D/t
NOCK
Section is out of the water and is thus not checked for hydrostatic conditions
10.2.3. ISO HYDR Nomenclature
ISO HYDR uses the following nomenclature:
10.2.3.1. ISO HYDR Nomenclature - Dimensional
10.2.3.2. ISO HYDR Nomenclature - Acting Section Forces and Stresses
10.2.3.3. ISO HYDR Nomenclature - Allowable Stresses and Unity Checks
10.2.3.4. ISO HYDR Nomenclature - Parameters
10.2.3.1. ISO HYDR Nomenclature - Dimensional
D
Tube outside diameter
t
Thickness
k
Effective length factor (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
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463
BEAMST ISO Theory
Lu
Unstiffened length of member
L
Unbraced length of member (if subscripted with y or z, this relates to the appropriate local axis, if not
it is the maximum)
i
Radius of gyration (if subscripted with y or z, this relates to the appropriate local axis, if not it is the
maximum)
10.2.3.2. ISO HYDR Nomenclature - Acting Section Forces and Stresses
σac
Design axial stress including effect of hydrostatic capped axial stress
σa
Design axial stress
σq
Capped end axial design compression due to external hydrostatic pressure
σmy, σmz
Design bending stress about local y and z axes
σp
Design hoop stress due to hydrostatic pressure
σm
Design bending stress
10.2.3.3. ISO HYDR Nomenclature - Allowable Stresses and Unity Checks
fh
Characteristic hoop buckling strength
fhe
Elastic hoop buckling strength
fm
Characteristic bending strength
fcl
Characteristic local buckling strength
fcle
Characteristic elastic local buckling strength
fc
Characteristic axial compressive strength
464
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
fclR
Design local buckling strength
fchR
Design axial compressive strength in the presence of external hydrostatic pressure
fmh
Design bending resistance in the presence of external hydrostatic pressure
fEy, fEz
Euler buckling strength for y and z axes
fy
Yield stress
UCc1,c2,c3
Combined axial (tension or compression), bending and hydrostatic pressure checks
UCh
Hoop compressive unity check
10.2.3.4. ISO HYDR Nomenclature - Parameters
E
Young’s modulus
Ch
Critical hoop buckling coefficient
Column slenderness parameter
Cmy, Cmz
Moment amplification reduction factors
γh
Partial resistance factor for hoop buckling strength
10.2.4. ISO Unity Checks
In the hydrostatic collapse check the following assumptions are made:
1. All members are unflooded.
2. Out-of-roundness is assumed to be within API RP2B tolerance limits.
3. Wave crest is assumed to be directly above the beam section position under consideration.
4. Hydrostatic pressure is only considered for beam section positions below the static water level (= mean
water level + tide height + storm surge height).
5. The wave length, Lw, is adequately described by linear wave theory as follows:
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465
BEAMST ISO Theory
a. If
(shallow water)
then
b. Else if
and
(deep water)
then
c. Else Lw is obtained iteratively from
where:
(b)
Else Lw is obtained iteratively from
• d = static water depth
• g = acceleration due to gravity
• Tw = wave period
10.2.4.1. ISO HYDR - Design Hydrostatic Pressure
Clause/(Eqn)
Commentary
Message
The design head is given by
(13.2-21)
where
Hw = wave height
466
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
Clause/(Eqn)
Commentary
Message
z = depth below static water surface
The design head induced hoop stress is given by
(13.2-22)
(13.2-20)
where
10.2.4.2. ISO HYDR - Limit Checks
Clause/(Eqn)
Commentary
(13.1)
Message
DTRF
THKF
If t < 6mm
10.2.4.3. ISO HYDR - Elastic Hoop Buckling Strength, fhe
Clause/(Eqn)
Commentary
Message
If
then
If
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467
BEAMST ISO Theory
Clause/(Eqn)
Commentary
Message
(13.2-26)
then
If
then
If
then
10.2.4.4. ISO HYDR - Characteristic Hoop Buckling Strength, fh
Clause/(Eqn)
Commentary
(13.2-25)
If
(13.2-24)
Message
then
(13.2-23)
else
10.2.4.5. ISO HYDR - Hoop Compressive Unity Check, UCh
Clause/(Eqn)
Commentary
Message
(13.2-31)
where γh = 1.25
468
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
10.2.4.6. ISO HYDR - Combined Tension and Hydrostatic Pressure Unity Check
Clause/(Eqn)
Commentary
Message
Method A (Hydrostatic capped-end axial stress excluded)
Net axial tension condition,
(13.4.12)
where
Design tensile resistance in presence of external hydrostatic
pressure
(13.4.8)
where γt = 1.05
Design bending resistance in presence of external hydrostatic pressure
(13.2-9)
(13.2-10)
where fm is computed according to equations (13.2-13)
to (13.2-15). See ISO member checks for details.
γb = 1.05
(13.2-11)
Net axial compression condition,
(13.2-19)
(13.2-21)
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469
BEAMST ISO Theory
Clause/(Eqn)
Commentary
Message
where
fcl is computed according to equations (13.2-8) to (13.29). See ISO member checks for details.
fcle is computed according to equations (13.2-10). See
ISO member checks for details.
γc = 1.18
If
then
Method B (Hydrostatic capped-end axial stress included)
Tension for σac
(13.4-12)
10.2.4.7. ISO HYDR - Combined Compression and Hydrostatic Pressure Unity Check
Clause/(Eqn)
Commentary
Message
Method A (Hydrostatic capped-end axial stress excluded)
σa = compression
(13.2-20)
(13.2-19)
470
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ISO Hydrostatic Member Collapse Checks (ISO HYDR)
Clause/(Eqn)
Commentary
Message
where
Design axial compressive strength in the presence of external hydrostatic pressure, fchR
(13.2-15)
(13.2-16)
then
else
Net axial compression condition,
If also
(13.2-21)
then
Method B (Hydrostatic capped-end axial stress included)
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471
BEAMST ISO Theory
Clause/(Eqn)
Commentary
Message
If
(13.2-20)
(13.2-19)
If also
then
(13.2-21)
(13.2-19)
If
then
(13.2-21)
472
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ISO Joint Strength Check (ISO JOIN)
10.3. ISO Joint Strength Check (ISO JOIN)
This section discusses the following topics:
10.3.1. ISO JOIN Overview
10.3.2. ISO Joint Check Report
10.3.3. ISO JOIN Nomenclature
10.3.4. ISO Joint Strengths and Unity Checks
10.3.5. ISO JOIN - Interpolated Joints
10.3.1. ISO JOIN Overview
The ISO JOIN command requests that a joint check be performed to the ISO code of practice (Ref. 27).
The joints may consist of TUBE elements and/or other beam types that have been assigned tubular
sections in the structural analysis.
Joints for the ISO check post-processing are selected using the JOINt command in BEAMST which specifies
the node numbers at joint positions. All joints are assumed ‘simple’. Elements may be excluded from
the joint punching shear check using the SECOndary command.
Joints are automatically classed as a combination of K, T or Y depending on the loading applied. A
maximum of 5 types per brace member is permitted; results are produced for each brace forming the
joint.
1. The chord member is the member with the greatest outside diameter.
2. If two or more potential chord members have equal diameters; BEAMST will consider the two with the
largest wall thicknesses and for each loadcase selected will check the one most heavily stressed against
all brace members.
3. In the case of two or more potential chord members with equal diameters and wall thicknesses, the first
two encountered as shown in the Cross Check Report will be considered.
4. If the CHOR command is used to specify a chord member, this alone will be considered. If two chords
are specified, the most heavily stressed chord will be checked against all brace members for each loadcase
selected.
5. All members not selected as chord members are treated as brace members (unless defined as secondary),
with each brace-chord pair being checked.
A joint is formed of a maximum of 3 nodes connected by valid chord members. These nodes must form
a straight line and must be within a distance of D/4. This process is performed automatically, however,
if required can be specified manually using the CHOR command.
All valid members that form the joint are allocated to a number of planes. A tolerance of +/- 15° exists
to identify braces belonging to the same plane. Each member in each plane is then assessed to obtain
unity factors for axial and bending forces in addition to an interaction ratio to account for the combination of such forces.
BEAMST automatically decides on the type of joint by assessing the balancing axial force in each valid
brace member forming the joint. Firstly any load paths that form a K joint are assessed; it can be the
case that in a traditional KT Joint shape that this will result in 2 K joints with different gaps between
members.
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473
BEAMST ISO Theory
All forces that transfer across the joint to an opposite brace will form X Joints; again it is possible that
multiple X Joint load paths co-exist within one joint; in this case these will be calculated with the appropriate offsets. Finally, any shear that exists in a joint will be accounted for by the provision of a Y
joint type. The final joint capacity will be calculated using the proportion of axial load that is allocated
to each of the joint types.
BEAMST will only check selected joints in which two or more incident members are tubular and of circular section. All other selected joints are automatically bypassed.
The user may override these classifications using the TYPE and CHOR commands. Interpolated joint
classifications may be defined using the TYPE command. For K joints a gap dimension appropriate to
the joint may be specified in the TYPE command. A default gap dimension may be specified using the
GAPD command.
The ISO standard utilizes limit state checks with partial resistance factors to achieve the desired level
of safety. In keeping with this principle, applied loads must be multiplied by appropriate partial action
factors, as defined in the code of practice, to develop the design load case combinations necessary for
processing. Where non-linear pile analysis is undertaken (e.g. using SPLINTER) the design loads must
be applied to the pile model to account for the increased non-linearity this introduces. In situations
where a non-linear pile analysis has not been carried out, the design loads may be produced using the
COMB or CMBV commands utilizing the required load factors. For abnormal loading conditions the
ABNO command may be used to set the partial resistance factors to unity.
The detailed joint check report provides information on joint geometric parameters, type, acting chord
and brace stresses, punching shear, Qf and Qu factors, punching shear allowable(s), and unity checks.
This may be requested using the PRINt UNCK command. The maximum unity check is flagged for ease
of reference. When an interpolatory joint type classification is being employed two sets of punching
shear allowables are reported, one for each joint classification type and these pertain to joints classified
as 100% of the respective joint types.
Summary report 3 comprises the highest unity check for each selected loadcase for each joint.
Summary report 4 comprises the three worst unity checks for each selected joint, together with the
distribution of unity check values. This distribution provides information on the number of unity checks
exceeding an upper limit (default 1.0), less than a lower limit (default 0.5), and the number in the mid
range.
BEAMST commands applicable to the ISO joint check are given in Table 10.4: ISO JOIN Commands (p. 474)
below and are described in detail in BEAMST Command Reference (p. 51). An example data file is given
in Example 10.3: Example of an ISO JOIN data file (p. 475).
Table 10.4: ISO JOIN Commands
Command
Description
Usage
ISO JOIN
ISO joint check header command
C
UNIT
Units of length and force
C
YIEL
Yield stress
JOIN
Joint numbers to be reported
TYPE
Joint type and brace element definition
CHOR
Chord elements at a joint
474
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Note
1
ISO Joint Strength Check (ISO JOIN)
Command
Description
Usage
Note
SECO
Secondary members to be ignored in checks
DESI
Defines design section properties
GAPD
Defines default gap dimension
PROF
Section profiles for use in design
STUB
Tubular member end stub dimensions
ABNO
Abnormal loadcases
CASE
Basic loadcases to be reported
C
3
COMB
Define a combined loadcase for processing
C
3
CMBV
Define a combined loadcase for processing
C
3
SELE
Select/redefine a combined/basic loadcase title
RENU
Renumber a basic loadcase
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one CASE, CMBV or COMB command must be included.
Example 10.3: Example of an ISO JOIN data file
SYSTEM DATA AREA 200000
TITLE Beamst verification test for ISO 19902
t2216be1.dat 23/01/2009
TEXT *************************************************************************
TEXT ISO TEST FOR JOINTS
t2216be1.dat
TEXT CREATED 23/01/09
TEXT
TEXT ASSOCIATED FILES
TEXT T2216ASA.DAT ASAS ANALYSIS SIMPLE STRUCTURE FOR JOINTS
TEXT T2216BE1.DAT BEAMST JOINT ANALYSIS SAVE FEMV FILES
TEXT T2216BE2.DAT BEAMST JOINT ANALYSES CHORD EFFE COMMAND, UNITS
TEXT *************************************************************************
JOB OLD POST
PROJECT
T216
STRUCTURE T216
OPTIONS GOON
UNITS
KN
M
SAVE FEMU FILES
END
ISO ED1 JOIN
PRINT ALL
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of ANSYS, Inc. and its subsidiaries and affiliates.
475
BEAMST ISO Theory
PRINT UNCK SUM1 SUM3
COMB 2 7.0 1
YIEL
345000.0
GROU
ALL
JOIN
752
CHOR
752
745
746
YIEL
340000.0
ELEM
745
YIEL
340000.0
ELEM
746
STUB
END2
1.2000
STUB
END1
1.2000
STUB
END2
1.0000
*TYPE
752
K
751
* REPLACED FOR NORSOK WITH
TYPE
752
K
751 755
STUB
END1
1.0000
*TYPE
752
K
755
* REPLACED FOR NORSOK WITH
TYPE
752
K
755 751
STUB
END2
1.0000
TYPE
752
X
585
ALL
STUB
END2
1.0000
TYPE
752
X
586
ALL
STUB
END1
1.0000
TYPE
752
X
785
ALL
STUB
END1
1.0000
TYPE
752
X
786
ALL
JOIN
712
CHOR
712
501
601
YIEL
415000.0
ELEM
501
YIEL
415000.0
ELEM
601
STUB
END2
2.0000
STUB
END1
2.0000
STUB
END1
1.2000
TYPE
712
T
745
ALL
JOIN
785
CHOR
785
743
744
YIEL
340000.0
ELEM
743
YIEL
340000.0
ELEM
744
STUB
END2
1.2000
STUB
END1
1.2000
STUB
END2
1.0000
TYPE
785
Y
757
ALL
JOIN
956
CHOR
956
962
963
YIEL
345000.0
ELEM
962
YIEL
345000.0
ELEM
963
STUB
END2
1.0000
STUB
END1
1.0000
STUB
END2
1.0000
TYPE
956
X
961
ALL
JOIN
956
CHOR
956
962
963
YIEL
345000.0
ELEM
962
YIEL
345000.0
ELEM
963
STUB
END2
1.0000
STUB
END1
1.0000
STUB
END1
1.0000
TYPE
956
X
964
ALL
END
STOP
0.0300
ELEM
0.0300
ELEM
0.0200
ELEM
0.0000
ALL
0.0000
ALL
0.0200
ELEM
0.0000
ALL
0.0000
ALL
0.0200
ELEM
745
746
751
755
585
0.0200
ELEM
586
0.0200
ELEM
785
0.0200
ELEM
786
0.0400
0.0400
0.0300
ELEM
ELEM
ELEM
501
601
745
0.0300
0.0300
0.0200
ELEM
ELEM
ELEM
743
744
757
0.0200
0.0200
0.0200
ELEM
ELEM
ELEM
962
963
961
0.0200
0.0200
0.0200
ELEM
ELEM
ELEM
962
963
964
10.3.2. ISO Joint Check Report
The detailed JOINT check report provides information on joint geometric parameters, type, acting chord
and brace loading, Qf, and Qu factors, nominal load allowables and unity checks. This may be requested
using the PRINt UNCK command. The maximum unity check is flagged for ease of reference.
Messages displayed in output reports or obtained from the database have the following meanings:
476
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ISO Joint Strength Check (ISO JOIN)
FAIL
Unity check value exceeds unity
PNT9
Unity check value exceeds 0.9
MEMB
Joint utilization exceeds brace utilization assuming that the latter is conservatively taken as unity. More
detail check is required, which is not currently undertaken by the program.
NOCK
No check has been carried out, due to one of the following error messages:
BETA
Beta value β is outside the valid ISO range1 (Checks can continue with OPTI JRNG)
THET
Theta value θ is outside the valid ISO range1 (Checks can continue with OPTI JRNG)
GAMA
Gamma value γ is outside the valid ISO range1 (Checks can continue with OPTI JRNG)
TAU
Tau value τ is outside the valid ISO range1 (Checks can continue with OPTI JRNG)
NOCY
Computed Py value is less than zero
DIST
The distance between work points exceeds D/42
10.3.3. ISO JOIN Nomenclature
ISO JOIN uses the following nomenclature:
10.3.3.1. ISO JOIN Nomenclature - Dimensional
10.3.3.2. ISO JOIN Nomenclature - Acting Forces and Stresses
10.3.3.3. ISO JOIN Nomenclature - Allowable Stresses and Unity Checks
10.3.3.4. ISO JOIN Nomenclature - Parameters
1
Error message
2
Warning message
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477
BEAMST ISO Theory
10.3.3.1. ISO JOIN Nomenclature - Dimensional
D
Chord outside diameter
d
Brace outside diameter
R
Chord radius
T
Chord thickness
t
Brace thickness
γ
Ratio between the chord radius and thickness
τ
Ratio between the thickness of the brace and chord
θ
Angle between brace and chord
β
Ratio between the diameter of the brace and chord
g
K joint gap
10.3.3.2. ISO JOIN Nomenclature - Acting Forces and Stresses
P
Brace axial force
Mip
Brace in-plane bending moment
Mop
Brace out-of-plane bending moment
478
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ISO Joint Strength Check (ISO JOIN)
Paxc
Chord axial force
Mipc
Chord in-plane bending moment
Mopc
Chord out-of-plane bending moment
fa
Brace axial stress component
fip
Brace in-plane bending stress
fop
Brace out-of-plane bending stress
fb
Resultant brace bending stress
10.3.3.3. ISO JOIN Nomenclature - Allowable Stresses and Unity Checks
fy
Chord yield stress
fyb
Brace yield stress
PRd
Allowable axial force
MRdip
Allowable in-plane bending moment
MRdop
Allowable out-of-plane bending moment
Pyc
Chord yield force
Mpc
Chord plastic moment
UCax
Axial force unity check
UCip
In-plane bending unity check
UCop
Out-of-plane bending unity check
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479
BEAMST ISO Theory
UCBN
Combined bending unity check
10.3.3.4. ISO JOIN Nomenclature - Parameters
γq
Partial resistance factor for yield strength
γj
Partial resistance factor for joints
γz
Extra partial resistance factor to ensure that members fail before the joint yields
10.3.4. ISO Joint Strengths and Unity Checks
This section discusses the following topics:
10.3.4.1. ISO JOIN - Chord Action Factor, Qf
10.3.4.2. ISO JOIN - Strength Factor Qu
10.3.4.3. ISO JOIN - Characteristic Resistances
10.3.4.4. ISO JOIN - Nominal Load Unity Checks
10.3.4.5. ISO JOIN - Combined Axial and Bending Unity Checks
10.3.4.1. ISO JOIN - Chord Action Factor, Qf
Clause/(Eqn)
Commentary
Message
(14.3-9)
If
NOCY
where
λ = 0.030 brace axial force = 0.045 brace inbending =
0.021 brace outbending
(14.3-10)


=    +   +     
     






γq = 1.05
For brace axial force:
C1 = 25 for Y joints
= 20 for X joints
= 14 for K joints
C2 = 11 for Y joints
480
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ISO Joint Strength Check (ISO JOIN)
Clause/(Eqn)
Commentary
Message
= 22 for X joints
= 43 for K joints
For brace moments:
C1 = 25
C2 = 43
10.3.4.2. ISO JOIN - Strength Factor Qu
Clause/(Eqn)
Commentary
(14.3.3)
If β > 0.6
Message
then
else Qβ = 1.0
For K joints
Gap factor
If
then
elseif
then
where
else then Qg is linearly interpolated between the limiting
values for the ratio g/T
Qu is obtained from:
For moment calculations, all joint types:
In-plane bending:
Out-of-plane bending:
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481
BEAMST ISO Theory
Clause/(Eqn)
Commentary
Message
For axial calculations, K joints:
For axial calculations, T/Y joints:
In axial tension:
In axial compression:
For axial calculations, X joints:
In axial tension:
else
In axial compression:
10.3.4.3. ISO JOIN - Characteristic Resistances
Clause/(Eqn)
(14.3-1)
(14.3-2)
(14.3-11)
Commentary
Message
= =
where γj = 1.05
For Y and X joints where a joint can is specified:
482
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ISO Joint Strength Check (ISO JOIN)
Clause/(Eqn)
Commentary
Message
where
PRdCan from (14.3-1) is based on chord can geometric
properties
Tn = Nominal chord member thickness
Tc = Chord can thickness
If β ≤ 0.9
then
else
Lc = Effective total length
10.3.4.4. ISO JOIN - Nominal Load Unity Checks
Clause/(Eqn)
Commentary
Message
Unity checks are calculated for each component of brace
loading; that is:
If any UC > 0.9 but < 1.0....................................
If any UC > 1.0 ................................................
PNT9
FAIL
10.3.4.5. ISO JOIN - Combined Axial and Bending Unity Checks
Clause/(Eqn)
Commentary
(14.3-12)
(14.3-13)
Message
PNT9
If UCBN > 0.9 but < 1.0....................................
FAIL
MEMB
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483
BEAMST ISO Theory
Clause/(Eqn)
Commentary
Message
If UCBN > 1.0 ................................................
If
................................................
UB = Utilization of the brace at the joint end and conservatively taken as 1.0
γz = 1.17
10.3.5. ISO JOIN - Interpolated Joints
Clause/(Eqn)
Commentary
Message
If an interpolatory joint type classification is specified or
identified, the design strengths are calculated from:
484
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Chapter 11: BEAMST POST Theory
The POST header command in BEAMST is used to request post-processing (other than checks to design
codes of practice) to produce intermediate member forces and moments, and to compute section
stresses for all currently supported section profiles.
11.1. POST Command Data (POST)
This section discusses the following topics:
11.1.1. POST Overview
11.1.1. POST Overview
The POST header command in BEAMST is used to request post-processing (other than checks to design
codes of practice) to produce intermediate member forces and moments, and to compute section
stresses for all currently supported section profiles.
In general the POST Command data block will contain the following; a POST header command, a UNIT
command defining the units of length and force used (see BEAMST Command Reference (p. 51) and
BEAMST Command Sets (p. 54)), ELEMent, GROUp and CASE commands selecting elements, groups and
loadcases for processing and possibly a DESI command (BEAMST Command Reference (p. 51)) if the
stress report is requested for elements other than TUBE which have not been defined using sections in
the structural analysis. Combinations of loadcases may also be included in the reporting using the
COMBine or CMBV commands. Loadcases are assumed by default to be linear static. Spectral cases must
be defined using the SPECtral command.
The selection of output reports is made using the PRINt command with the appropriate parameters for
the required reports. The command may also be used to request summary report 5, using the PRIN
SUM5 command, which provides information about the highest member forces and moments for each
selected group.
The complete list of commands applicable to the POST Command is given in Table 11.1: POST Commands (p. 485) below and are described in detail in BEAMST Command Reference (p. 51). An example
data file is shown in Example 11.1: Example of a POST data file (p. 486).
Table 11.1: POST Commands
Command
Description
Usage
Note
POST
BEAMST Post-processing Header command
C
UNIT
Units of length and force
GROU
Groups to be reported
C
2
ELEM
Elements to be reported
C
2
SECT
Sections to be reported
DESI
Defines design section properties
C
3
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485
BEAMST POST Theory
Command
Description
Usage
Note
PROF
Section profiles for use in design
CASE
Basic loadcases to be reported
C
4
COMB
Define a combined loadcase for processing
C
4
CMBV
Define a combined loadcase for processing
C
4
SELE
Specify a loadcase title
SPEC
Select loadcases for a spectral analysis
RENU
Renumber a ‘basic loadcase’
PRIN
Reports to be printed
TEXT
Text or comment command
TITL
Redefine global title
END
Terminates command data block
C
Usage
C Compulsory command, but see notes below where applicable.
Notes
1. See the Command Reference section, specifically the UNIT command.
2. At least one GROUP or ELEM command must be included.
3. Compulsory for non-tubulars unless sections have been used for all elements to be processed in the
preceding analyses.
4. At least one CASE, CMBV or COMB command must be included.
Example 11.1: Example of a POST data file
SYSTEM DATA AREA 100000
JOB POST
PROJECT MANU
FILES BEJA
STRU
COMPONENT PILE DECA
OPTION GOON
END
UNITS KN M
END
POST
*
* Select all elements using the GROUP command except
* elements 991 and 992 - dummy elements
*
GROUP ALL
NOT ELEMENT 991 992
*
* Define section properties for some elements that
* used areas and inertia values in the ASAS run
* Section dimensions in mm
*
UNITS MM
486
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POST Command Data (POST)
DESI RHS 900.0 400.0 40.0 ELEMENT 851 TO 854 861
: 931 TO 942
*
* Switch units back to M
*
UNITS M
*
* Examine two load cases including jacket loading
*
SELE 10 Extreme Wave 1 + Dead Loads + Topside Loads
COMB 10 1.0 1 1.0 3 1.0 4
SELE 11 Extreme Wave 2 + Dead Loads + Topside Loads
COMB 11 1.0 2 1.0 3 1.0 4
*
* Check mid-span and quarter point sections
*
SECT 0.25 0.5 0.75 ELEM ALL
*
* Ask explicitly for all reports
*
PRIN XCHK PROP FORC STRE SUNI N MM
END
STOP
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487
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Chapter 12: BEAMST Appendices
This section discusses the following topics:
12.1. Running BEAMST
12.2. Section Descriptions
12.3. Graphical Display of BEAMST Results
12.4. Using BEAMST in Stand-Alone Mode
12.5. BEAMST References
12.1. Running BEAMST
This section discusses the following topics:
12.1.1. ASAS Files Required by BEAMST
12.1.2. Files required by BEAMST in Stand-Alone Mode
12.1.3. Files Produced by BEAMST
12.1.4. Saving Plot Files Produced by BEAMST
12.1.1. ASAS Files Required by BEAMST
BEAMST operates on the files produced by a preceding ASAS, RESPONSE or LOCO analysis and hence
these files must physically be present in the user’s working directory for the program to run successfully.
In all cases the project file must exist which contains information about all other files in the current set
of analyses. The name of this file is derived from the four character Project Name defined on all the
PROJECT commands in the set. (For example, if the Project Name is PRKZ, then the Project File will be
PRKZ1O).
For each ASAS, RESPONSE and LOCO analysis preceding this run with a ‘SAVE BEAMST FILES’ command
in its preliminary data block, there will be a physical file containing forces and moments from that
analysis. Again the physical file names are derived from the four character name defined on the FILES
command. Typically, if the names used were STVK, SQSY and TBSS then the physical files would be
STVK35, SQSY35 and TBSS35. The information stored in each file will depend on the form of the run
producing the output. The forces and moments may relate to a the analysis of a structure or to the
results associated with the elements at any level in a sub-structured analysis. Provided that the user
has the requisite files in their working directory the program will handle them in a transparent manner.
The preceding analysis must have run to completion. If the run did not complete either because of a
failure or because the user terminated the run deliberately with a RESTART command, BEAMST may
error because some files may not exist.
12.1.2. Files required by BEAMST in Stand-Alone Mode
In stand-alone mode, all the required data must be provided in the input datafile and no other files are
needed.
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BEAMST Appendices
12.1.3. Files Produced by BEAMST
In addition to the standard printed output file which contains the main detailed reports, a second output
file containing the summary reports is produced. This file is named xxxxBM where xxxx is the fname
parameter from the FILES command.
12.1.4. Saving Plot Files Produced by BEAMST
The results from a BEAMST run may be saved for plotting using the FEMVIEW program. See SAVE
command and Graphical Display of BEAMST Results (p. 502) for further details.
12.2. Section Descriptions
This appendix gives details of the dimensional data required to define each section type available in
BEAMST and also the equations used to calculate flexural properties and member stresses. The following
nomenclature is used:
Dimensional:
d = Section depth (in local Y direction)
b = Section width (in local Z direction)
t, tw, tf = Thickness; wall, web, flange
D, ID, Dn = Tube diameters; outer, inner, nominal
ry, rz, rt = Radii of gyration; bending Y, bending Z, torsional
Flexural:
Ax, Ay, Az = Section area; cross section, Y and Z shear areas
Ix, Iy, Iz = Sectional inertias; torsional, minor and major bending
Acting Forces and Stresses:
Fx = Axial force
Mx, My, Mz = Moments; torsion, minor (Y) bending, major (Z) bending
Qy, Qz = Shear forces Y,Z
fa = Computed axial stress
fby, fbz = Computed bending stresses in Y/Z local bending planes
ftx = Torsion shear for tubes
fty, ftz = Torsion shear in web and flange plates of boxes
fvy, fvz = Shear stresses Y, Z
fbymax, fbzmax = Maximum computed bending stress anywhere along beam
fvm\x = Maximum shear stresses for tubes
Code Check Stresses:
fbyr, fbzr=Bending resultant
fb=Resultant bending stress
fh=Hoop compressive stress
fxt, fxc=Axial tension and compressive stresses in hoop compressed TUBES
fat, fac=Computed axial tension and compressive stresses
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Section Descriptions
Allowable Stresses:
E=Young’s modulus
Fa=Axial compression
Fbc, Fbt=Compressive, tensile bending stress
Fe=Euler buckling stress
Fv=Shear
FVB, FVY=Shear buckle, shear yield
Fy=Yield stress (minimum)
Other symbols are defined within the text.
12.2.1. TUB - Tubes of Circular Sections
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
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BEAMST Appendices
492
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Section Descriptions
See BEAMST DS44 Theory (p. 347) for Design Load Effects for DS449 checks.
See API Allowable - Acting Punching Shear Vp (p. 248) for calculations of acting punching shear for API
punching shear and brace end fatigue checks."
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BEAMST Appendices
12.2.2. FBI - Fabricated I-Section
Note: ry, rz and rT are optional. If omitted from the DESI or PROF commands they are calculated automatically.
494
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Section Descriptions
12.2.3. WF - Wide Flanged Rolled I-Section
Note: ry, rz and rT are optional. If omitted from the DESI or PROF commands they are calculated automatically.
Other flexural properties taken from ASAS data or from DESI or PROF commands.
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BEAMST Appendices
12.2.4. RHS - Rolled Hollow Section
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
Other flexural properties taken from ASAS data or from DESI or PROF commands.
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Section Descriptions
12.2.5. BOX - Fabricated Box Section
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
Other flexural properties taken from ASAS data or from DESI or PROF commands.
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BEAMST Appendices
12.2.6. PRI - Solid Rectangular Section
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
Other flexural properties taken from ASAS data or from DESI or PROF commands.
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Section Descriptions
12.2.7. CHAN - Channel Section
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
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BEAMST Appendices
Other flexural properties taken from ASAS data or from DESI or PROF commands.
12.2.8. TEE - Tee Section
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
500
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Section Descriptions
Other flexural properties taken from ASAS data or from DESI or PROF commands.
12.2.9. ANGL - Angle Section
Note: ry and rz are optional. If omitted from the DESI or PROF commands they are calculated automatically.
Flexural Property Formulae:
Flexural properties taken from ASAS data or from DESI or PROF commands.
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BEAMST Appendices
12.3. Graphical Display of BEAMST Results
The results from a BEAMST run may be presented graphically by FEMVIEW. A plot file for this program
is created when the SAVE FEMS FILES command is included in the BEAMST preliminary data. This facility
is restricted to BEAMST data files containing only one complete data set (ie not multiple check types
in a single run) and for static (not spectral) loadcases.
12.3.1. BEAMST Plot Files
The data written to the plot file falls into three categories:
• Structural Description
• Member Forces
• Unity Check Values
The format for this data is as follows:
a. Structural Description
The complete structural data for the current structure (as defined in the preliminary data) is saved
irrespective of the subset of members/joints specified in the BEAMST data. This enables the results
to be presented on the structure as a whole and allows further results to be appended to the
model. This data includes the node numbers, associated coordinates and element data.
b. Member Forces
Member forces (and moments) are written to the plot file when the FORC option is included in the
PRIN command. Results are written for all processed elements at the element end points and any
intermediate sections at which forces are evaluated. All the results are written for each element in
502
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Graphical Display of BEAMST Results
turn, each individual result being identified by an abbreviated name. These identifiers are given in
Table 12.1: Member Force Abbreviations/Force Numbers (p. 503).
Table 12.1: Member Force Abbreviations/Force Numbers
Result Type
FEMVIEW Abbreviation
Axial Force (FX)
TEN_COMP
Shear in local Y
SHEAR_Y
Shear in local Z
SHEAR_Z
Torsion (MX)
TORSION
Moment in local Y (MY)
MOMENT_Y
Moment in local Z (MZ)
MOMENT_Z
Resultant Shear (SP=(FY2+FZ2)½))
PRIN_SHR
Resultant Moment (MP=(MY2+MZ2)½)
PRIN_MOM
c. Unity Check Values
Unity check values are written to the plot file for the requested code checks. For FEMVIEW the checks
are identified for selection by an abbreviated name and identified on the plots by a check number.
The identification abbreviations and numbers are given in Table 12.2: Unity Check Abbreviations/Check
Numbers (p. 503).
Table 12.2: Unity Check Abbreviations/Check Numbers
Check Type
AISC ALLO
API WSD ALLO
API LRFD MEMB
Member Type
Unity Check
FEMVIEW Abbreviation
Check Number
Axial
AXIAL
1
TUB
Shear y
SHEAR_Y
2
WF
Shear z
SHEAR_Z
3
RHS
Pure Bending y
P.BEND_Y
4
BOX
Pure Bending z
P.BEND_Z
5
FBI
Maximum Shear
MX.SHEAR
6
Combined Buckle
CMB.BUCK
7
Combined Yield
CMB.YLD
8
True C.S.R
TRUE.CSR
9
Axial
AXIAL
1
Shear
SHEAR
2
Torsion
TORSION
3
Pure Bending y
P.BEND_Y
4
Pure Bending z
P.BEND_Z
5
Resultant Bending
RES.BEND
6
Combined Buckle
CMB.BUCK
7
Combined Yield 1
CMB.YLD1
8
Combined Yield 2
CMB.YLD2
9
TUB
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Check Type
AISC LRFD MEMB
AISC WSD HYDR
Member Type
Unity Check
FEMVIEW Abbreviation
Check Number
True C.S.R
TRUE.CSR
10
Axial
AXIAL
1
TUB
Shear y
SHEAR_Y
2
WF
Shear z
SHEAR_Z
3
RHS
Pure Bending Y
P.BEND_Y
4
BOX
Pure Bending Z
P.BEND_Z
5
FBI
Combined Yield
YIELD
6
Axial Compression
AX.COMP
21
Axial tension
AX.TENS
22
Hoop
HOOP
23
Combined Compression
CMB.COMP
24
Combined Tension
CMB.TENS
25
Axial
AXIAL
21
Hoop
HOOP
22
Yield
YIELD
23
Buckle
BUCKLE
24
Combined Compression
CMB.COMP
25
Combined Tension
CMB.TENS
26
Axial Tension
AX.TENS
11
TUB
Pure Bending z
P.BEND_Z
12
WF
Pure Bending y
P.BEND_Y
13
RHS
Combined Axial
and Bemding
CMB.AX+B
14
BOX
Shear z
SHEAR_Z
15
FBI
Shear y
SHEAR_Y
16
Buckle y
BUCKLE_Y
17
Buckle z
BUCKLE_Z
18
Torsional Buckling
TOR.BUCK
19
Compression and
Moment
COMP+MOB
20
WF
Direct
DIRECT
31
RHS
Shear y
SHEAR_Y
32
BOX
Shear z
SHEAR_Z
33
FBI
Von-Mises
VON.MISE
34
Yield
YIELD
35
TUB
BOX
API LRFD HYDR
TUB
BOX
BS59 MEMB
NPD MEMB
504
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Graphical Display of BEAMST Results
Check Type
Member Type
Unity Check
FEMVIEW Abbreviation
Check Number
NPD MEMB
TUB
Combined Axial +
Bending
CMB.AX+B
36
Combined Axial +
Pressure
CMB.AX+P
37
Combined Axial +
Torsion Shear
CMB.AX+TS
38
Combined Axial +
Bending Shear
CMB.AX+BS
39
NPD MEMB
TUB, WF, RHS,
BOX
Combined Member Buckle
CMB.M.BK
40
NPD MEMB
TUB
Maximum Buckle
MX.BUCKL
41
Von-Mises
VON.MISE
71
Shear
SHEAR
72
Buckling
BUCKLING
73
Local Buckling
LCL.BUCK
74
Hydrostatic Buckling
HYD.BUCK
75
Combined Buckling
CMB.BUCK
76
Combined Axial
and Bending
CMB.AX+B
77
Combined Axial
and Pressure
CMB.AX+P
78
Axial
AXIal
51
In-plane Bending
IP.BEND
52
Out-of-plane
Bending
OP.BEND
53
Combined Bending
CMB.BEND
54
Combined Axial +
Bending
CMB.AX+B
55
Joint Check
JOINT.CK
56
Axial
AXIAL
51
In-plane Bending
IP.BEND
52
Out-of-plane
Bending
OP.BEND
53
DS44 MEMB
TUB
FBI
API WSD PUNC
TUB
API WSD NOMI
DS44 NOMI
API LRFD JOIN
TUB
54
Not used
Combined Axial +
Bending
CMB.AX+B
55
Joint Check
JOINT.CK
56
Cross Chord
Check
CROSS.CK
56
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Check Type
NPD JOIN
NORS MEMB
Member Type
TUB
TUB
Unity Check
FEMVIEW Abbreviation
Check Number
Axial
AXIAL
61
Combined Axial +
Bending
CMB.AX+B
62
Axial
AXIAL
61
Shear
SHEAR
62
Torsion
TORSION
63
Pure Bending y
Y_BEND
64
Pure Bending z
Z_BEND
65
Resultant Bending
RES.BEND
66
67
Not used
NORS HYDR
NORS PUNC
TUB
TUB
ALL
a
Combined Compr
+ Bend'g 1
YIELD_1
68
Combined Compr
+ Bend'g 2
YIELD_2
69
Combined Shear
+ Bending
CMB_SH+B
70
Combined Sh’r,
Bend’g + Tors
CMB_S+B+T
71
Hoop
HOOP_UC
81
Hoop and Axial
UCC1
82
Comb Hoop,
Bend’g + Axial 1
UCC2
83
Comb Hoop,
Bend’g + Axial 2
UCC3
84
Combined Unity
Check
COMB_UC
85
Axial
AXIAL
111
In-plane Bending
IP_BEND
112
Out-of-plane
Bending
OP_BEND
113
Combined Axial
and Bending
CMB_AX+B
114
Check Envelope
CK_ENVLP
0,50a
Check envelopes: 0 = maximum member unity check value; 50 = maximum joint unity check value.
12.3.2. Presenting BEAMST Results in FEMVIEW
The following section gives a brief overview of how BEAMST results may be presented in FEMVIEW. It
is not a substitute for the FEMVIEW User Manual which should be the reference for all use of FEMVIEW.
The FEMVIEW interface files must be read in at the ‘INDEX’ level using the command:
UTILITY READ VIEWDATA filename
506
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Graphical Display of BEAMST Results
The first file read must contain model data in addition to any results data unless the results are being
appended to an existing model. Once the data has been read and the FEMVIEW database created or
modified, FEMVIEW may be requested with the appropriate model name. Initially the outline of the
model will be displayed. It is often helpful to list the available results at this stage using the command:
UTILITY TABULATE LOADCASES
The loadcases are identified by the BEAMST loadcase number preceded by the letter L. In addition unity
checks create loadcase LMAX, this is an envelope case of the worst unity values from all the other
loadcases. The loadcase must be selected before any results may be displayed using the command:
RESULTS LOADCASE Ln
where ‘n’ is the loadcase number.
The unity check values presented in FEMVIEW are percentage values e.g. 40 represents 40% or 0.4.
12.3.2.1. Member Force Results
Member force results are created as gaussian results by BEAMST, one gauss point being located at each
member end, at each property step and at each selected element section. The components of force
(listed in Table 12.1: Member Force Abbreviations/Force Numbers (p. 503)) are selected individually by
the command:
RESULTS GAUSSIAN FORC_MOM comp
where ‘comp’ is the FEMVIEW abbreviation. Member force results may be presented by one of three
commands:
PRESENT DIAGRAM
Bending moment/Shear force diagrams
PRESENT NUMERIC
Numeric results on model plot
PRESENT GRAPH
Graph results (individual or string of elements)
Figure 12.1: Member Force Results Presented Diagramatically with Numerical Results Overlaid (p. 508)
and Figure 12.2: Member Force Results Presented Graphically for Element 5 (p. 508) show typical FEMVIEW
plots of member force results for an example model.
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BEAMST Appendices
Figure 12.1: Member Force Results Presented Diagramatically with Numerical Results Overlaid
Figure 12.2: Member Force Results Presented Graphically for Element 5
12.3.2.2. Member Unity Check Results
For each element processed in BEAMST there will be one unity check value per check type (as listed in
Table 12.2: Unity Check Abbreviations/Check Numbers (p. 503)). These are the worst unity check value
for the element and are stored as a gaussian result, the gauss point being at the location of this unity
value. In the case of buckling unity values, the position is always assumed at the center of the beam.
The results are selected by the command:
RESULTS GAUSSIAN checkname
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Graphical Display of BEAMST Results
where checkname is the FEMVIEW abbreviation of the unity check name.
Member unity check commands may only be presented in numerical form using the command:
PRESENT NUMERIC
This will display a plot of the model with the unity check value superimposed at each member center
and the unity value position on the member flagged by a small cross. The unity check value is presented
as a two or three part integer of the form:
ll/mm/nn
where:
‘ll’ is the loadcase number (only used when viewing loadcase LMAX)
‘mm’ is the check number (as shown in Table 12.2: Unity Check Abbreviations/Check Numbers (p. 503))
‘nn’ is the maximum unity check value for the element.
A typical member unity plot is show in Figure 12.3: Member Unity Checks Presented Numerically (p. 509)
Figure 12.3: Member Unity Checks Presented Numerically
12.3.2.3. Joint Unity Check Results
Joint unity check values are also in the form of element gaussian results. In this instance the unity values
refer to a particular member at a particular joint. The gauss point position is located 1/4 of the way
along the appropriate member from the joint to which the unity check value applies. A member may
have two values associated with it (one at each end) or none at all if it is not the critical member in the
joint. The results are selected, presented and interpreted as described above for member unity checks.
A typical joint unity check plot is shown in Figure 12.4: Joint Unity Checks Presented Numerically (p. 510)
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509
BEAMST Appendices
Figure 12.4: Joint Unity Checks Presented Numerically
12.4. Using BEAMST in Stand-Alone Mode
When BEAMST is run in stand-alone mode it is necessary to explicitly supply data in the BEAMST datafile
which is usually drawn from the ASAS database. The first part of this data is defined by the TOPO
command which specifies the user element number, the associated node numbers and the group
number. The element number is compulsory, the other data is optional but recommended. As element
numbers are used by other BEAMST commands it is necessary to set these up at the start of the BEAMST
data. For this reason the TOPO commands form their own command set must be positioned directly
after the Preliminary data and terminated by an END command. The TOPO ‘command set’ is followed
by the required code check command set, which along with the standard commands must also contain
further stand-alone specific commands. These commands and their use are summarized in the table
below:
Command
Description
Usage
TOPO
Define element number, nodes and group
C
END
Terminator for TOPO data
C
COOR
Defines nodal coordinates
MATE
Defines material data
FORC
Defines applied member loading
C
C
In addition to the above commands the DESI command (with PROF if required) is also mandatory to
define the element cross-section dimensions.
510
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BEAMST References
The header command for each command set consists of a keyword defining the design code, a second
keyword (or sub-header) defining the particular requirements from the code and in some instances
further keywords defining editions, amendments and check classes.
12.5. BEAMST References
Ref.
1
American Institute of Steel Construction, ‘Specification for Structural Steel
Buildings - Allowable Stress Design and Plastic Design’, Ninth Edition, 1st June,
1989.
Ref.
2
American Petroleum Institute, ‘Recommended Practice for Planning, Designing
and Constructing Fixed Offshore Platforms - Working Stress Design’, API RP2AWSD, Twentieth Edition, July 1st, 1993.
Ref.
3
American Petroleum Institute, ‘Recommended Practice for Planning, Design
and Constructing Fixed Offshore Platforms - Load and Resistance Factor
Design’, API RP2A-LRFD, First Edition, July 1st, 1993.
Ref.
4
British Standards Institute, ‘Structural Use of Steelwork in Buildings’, BS5950:
Part 1, 1985.
Ref.
5
Norwegian Petroleum Directorate, ‘Regulation for Structural Design of Loadbearing Structures Intended for Exploitation of Petroleum Resources’, 1985.
Ref.
6
Norwegian Petroleum Directorate, ‘Acts, regulations and provisions for the
petroleum activity’, January 1992.
Ref.
7
Norges Standardiseringsforbund, ‘Steel structures - Design rules’, NS3472E,
2nd edition, June 1984.
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BEAMST Appendices
Ref.
8
Norwegian Standard, ‘Prosjektering av bygningskonstruksjoner. dimensjonerende laster’, NS3479.
Ref.
9
Dansk Ingeniørforening, ‘Pile-Supported Offshore Steel Structures’, DS449,
September 1984.
Ref.
10
Dansk Ingeniørforening, ‘Structural Use of Steel’, DS412, March 1984.
Ref.
11
WS Atkins Engineering Software, ‘ASAS User Manual’, Version 12, February
2000.
Ref.
12
WS Atkins Engineering Software, ‘RESPONSE User Manual’, Version 12, February
2000.
Ref.
13
WS Atkins Engineering Software, ‘LOCO User Manual’, Version 12, February
2000.
Ref.
14
WS Atkins Engineering Software, ‘WAVE User Manual’, Version 12, February
2000.
Ref.
15
WS Atkins Engineering Software, ‘APCA User Manual’, Version 12, February
2000.
Ref.
16
WS Atkins Engineering Sciences, ‘ASAS-OFFSHORE, Technical Descriptions’,
Issue 2, March, 1983.
Ref.
17
Structural Stability Research Council, ‘Guide to Stability Design Criteria for
Metal Structures’, Ed. B.G. Johnston, J. Wiley and Sons, Third Edition, 1976.
Ref.
18
Atkins Research and Development, ‘The AISC Code, As Implemented in
BEAMST’, AAD Report No. 22.6.81.
Ref.
19
BCSA, ‘Combined Bending and Torsion of Beams and Girders’, Publication no
31 (first part), 1968.
Ref.
20
Horne MR, Morris LJ, ‘Plastic Design of Low-rise Frames’, CONSTRADO Monograph, 1981.
Ref.
21
Neal BG, ‘Plastic Methods of Structural Analysis’, 3rd Edition, Chapman & Hall,
1977.
Ref.
22
EEC International Committee for the development and study of tubular construction, ‘Construction with Hollow Steel Sections.’
Ref.
23
American Institute of Steel Construction, ‘Load and Resistance Factor Design
Specification for Structural Steel Buildings’, AISC LRFD, Second Edition,
December 1st, 1993.
Ref.
24
NORSOK Standard N-004, ’Design of Steel Structures’, (1st Edition, December
1998).
Ref.
25
American Institute of Steel Construction, ’Load and Resistance Factor Design
Specification for Steel Buildings’, AISC LRFD, Third Edition, Dec 27, 1999 with
errata Sept 4, 2001
Ref.
26
American Petroleum Institute, ’Recommended Practice for Planning, Design
and Constructing Fixed Offshore Platforms -Working Stress Design’, API RP2AWSD, Twenty-first edition, Dec 2000
Ref.
27
International Standard ISO 19902, 'Petroleum and Natural Gas Industries Fixed Steel Offshore Structures', 1st Edition, Dec 2007
512
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