Local Buckling of Cold-Formed Steel Members Under Pure Compression

The cold-formed steel (CFS) members can commonly attain failure due to instability in local, distortional, global or flexure. The existence of lateral restraining and specific boundary conditions on members can prevent or stimulate specific modes of instability in the member. The occurrence of any instability on the thin-walled members prevents these sections from attaining their full strength and leads to early failures. This research particularly focuses on compression member failure triggering due to local buckling. Member slenderness, material property and boundary condition can predominately influence the failure capacity of steel compression members. Numerical finite strip (CUFSM) and finite element (ABAQUS) based simulations are performed in order to identify the member geometry and for conducting non-linear simulations. A parametric study is conducted in order to investigate the effects of cross-section geometry, slenderness and steel grade on the member capacity under pure compression. The ability of the currently codified method presented in AS/NZS 4600 for predicting member ultimate load carrying capacity is verified for suitability with the obtained parametric study results.