GBT buckling analysis of generally loaded thin-walled members exhibiting arbitrary flat-walled cross-sections

A recently developed Generalized Beam Theory (GBT) formulation (Basaglia et al. 2013) is employed to perform buckling analyses of thin-walled members (i) exhibiting arbitrary flat-walled cross-sections, namely combinations of closed cells and open branches, and (ii) subjected to general loadings, including transverse loads acting away from the shear center axis. The above formulation, which is briefly presented in the first part of the paper, is employed to analyze the buckling behavior of two closed-cell beams namely (i) a RHS cantilever acted by two tip point loads and (ii) a closed-flange I-section simply supported beam subjected to a uniformly distributed load. In both cases, the loads are applied at the shear center axis and also at a parallel axes located at the top and bottom of the beam. The results presented and discussed, which consist of pre-buckling stress fields, buckling curves and buckling mode configurations, are obtained by means of the newly released code GBTUL 2.0 and validated by means of shell finite element analyses carried out in the code Ansys.