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Steel Portal Frame EC3 RUNET software
16.9 Design for SLS EN1993-1-1 § 7.2
The analysis for Serviceability Limit State (SLS), is performed by checking the deflections for all the SLS load cases after a first-order analysis.
Load combinations (SLS)
Ed = Gk + Qk1 + ψο·Qk2 + ψο·Qk3 (Characteristic combination)
(Eq.6.14b)
Ed = Gk + ψ1·Qk1 + ψ2·Qk2 + ψ2·Qk3 (Frequent combination)
(Eq.6.15b)
Ed = Gk + ψ2·Qk1 + ψ2·Qk2 + ψ2·Qk3 (Quasi-permanent combination)(Eq.6.16b)
The basic deflection checks are for the maximum vertical deflection in the apex and the maximum horizontal deflection at the top of the columns. The limits for these deflections are usually defined in the
National Annex. EN1993-1-1 § 7.2 and EN 1990 Annex A1.4
According to EN1993-1-1 these limits may be specified for each project and agree with the client.
The limits for deflections in the program can be specified in Parameters/Design parameters.
Usual values: vertical deflection L/200, horizontal deflection H/150, vertical deflection due to bending L/200.
16.10 Ultimate limit states ΕΝ 1993-1-1:2005 § 6.2
16.10.1 Tension ΕΝ 1993-1-1:2005 § 6.2.3
N
Ed
1
(ΕΝ 1993-1-1, 6.5)
N t
,
Rd
Design plastic resistance of the cross-section.
N pl
,
Rd
A
0
f y
(ΕΝ 1993-1-1, 6.6)
Design ultimate resistance of net cross-section at holes for fasteners.
N u
,
Rd
0 .
9
A net
f u
(ΕΝ 1993-1-1, 6.7)
M
2
A
area of cross-section
A net
area of net cross-section (minus holes)
f y
yield strength of steel
f
ultimate strength of steel
u
0
,
M
2
partial factors for material
16.10.2 Compression ΕΝ 1993-1-1:2005 § 6.2.4
N
Ed
1
(ΕΝ 1993-1-1, 6.9)
N c
,
Rd
N c
,
Rd
A
M
0
fy
for class 1, 2, 3 cross-sections (ΕΝ 1993-1-1, 6.10)
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