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Steel Portal Frame EC3 RUNET software
13.4 Structure data
13.4.1 Basic structure dimensions
Bay width L [m], the distance between column axes.
Total height H [m] and column height H1 [m] at axis points. If the frame is flat then H=H1. In this case specify first H1 and the H equal to H1.
Total transverse length B [m]. Is needed to evaluate the loading on the lateral bracing system, from wind or seismic loading.
Spacing s [m] of frames, transverse distance of column axis. Is uses as free span for purlins. For n frames B=(n-1)s.
Type of support. Pinned or fixed. Most common is the pinned support. The base connection and anchoring is simpler and the foundation smaller. In case of fixed support the base bending moment can be quite large for the base anchoring system or the fundament.
The size of the haunch is specified by selecting one of the ratios
(1/20, 1/10, 1/8, 1/6.6). This represents the horizontal size of the haunch measured from the axis of the column to the start point (h=raft height). The height of the haunch at the point of the junction with the column flange is always set to 2 times the rafter height (2xh). If you don’t want to specify haunch (as in flat frames) select the last option 0xL.
The cladding is supported on purlins. The thickness of the sheeting tw [mm] and the profile height hw [mm] are used for estimating the degree of lateral restrain of the purlins.
The spacing of purlins is the distance between the purlin axes. The section of purlins must be a symmetric section. If you select purlin
laterally unrestrained then the possible restraining of the purlin due to sheeting is disregarded. If you select purlin laterally restrained then the restraining due to sheeting is evaluated and used for wind pressure (sagging), and for the purlin is considered laterally unrestrained for wind uplift (hogging). For the evaluation of the dimensioning bending moments and shear forces you may choose Simply supported purlin or
Continuous purlin. In the second case the purlin is considered continuous over many spans.
The spacing of the lateral bracing for columns and torsional bracing for rafters is used for the lateral-torsional buckling design.
Check the way they applied in parameters/design parameters.
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