Lipped Channel, Hat, Zed and Rack Cold-Formed Steel Columns Under Local-Distortional Buckling Interaction

Resumo

Cold-Formed Steel (CFS) are usually thin-walled structural members, susceptible to several individual buckling
phenomena, namely local (L), distortional (D), global (G) (flexural or flexural-torsional) or interaction buckling

behavior, denominated local-distortional (LD), local-global (LG), distortional-global (DG) and local-distortional-
global (LDG) interactive buckling modes. The currently codified design approaches are able to handle single local

(L), distortional (D) and global (G) modes, as well as local-global (LG) interaction buckling failure. The buckling
mode interaction may conduct to erosion of the column strength, if compared to isolated single modes, and must
be taken into account in the structural design practice. The present work is aimed to propose a design approach for
CFS columns undergoing LD interaction, condition not considered by the Brazilian code ABNT NBR14762:2010.
The authors’ developed equations for LD design approach for CFS lipped channel columns were tested for other
CFS shapes, in order to expand its validity to usual CFS geometries, as zed, hat and rack. The obtained results and
the validation of the proposed solution proved to be easy to apply and reliable in predicting the column strength
of the most usual CFS.