Buckling Studies of Thin-Walled Channel Sections under Combined Bending and Shear (No. R886)

Thin-walled section members can be subjected to axial force, bending and shear. In the cases of cantilever beams and continuous lapped purlins, where combined bending and shear occur at the purlin section just outside the end of the lap, thin-walled sections may buckle at a lower stress than if only one action was present without the other. The computational modelling of the thin-walled steel sections is implemented by means of a spline finite strip analysis to determine the elastic buckling stresses of channel sections subject to bending and shear alone and interaction relations under combined bending and shear. Both unlipped and lipped channels are studied where the main variables are the flange width, different boundary conditions and shear flow distribution. Comparisons between cases, and with classical solutions are included in this report