ABSTRACT
An investigation on the distortional post-buckling behaviour of cold-formed steel Z-section columns and beams is presented. All the results are obtained by means of geometrically non-linear analyses based on a recently developed GBT formulation, which incorporates (i) conventional (shear undeformable), (ii) shear (non-linear warping) and (iii) transverse extension deformation modes. The results presented, most of which are compared with shell-element FEM analyses (for validation purposes), include post-buckling equilibrium paths and the evolution, along those paths, of the member deformed configuration and relevant displacements or stresses. Taking advantage of the GBT unique modal features, these results are discussed in great detail and it is possible to unveil, explain and/or shed some new light on a number of interesting and scarcely known phenomena.
