Interaction between local and distortional buckling modes in cold-formed steel members subjected to pure bending

This paper presents a numerical investigation on the interaction between local and distortional buckling in cold–formed steel sections. The effect of local buckling of compression flange on distortional buckling of compression flange and lip system is investigated using finite element methods. The analyses include the elastic linear buckling analysis to obtain the critical load of bifurcation buckling and the elastic non–linear analysis to obtain the limit point load of snap–through buckling. Influence of the local buckling on the post–distortional buckling is discussed. Initial geometric imperfection sensitivities of the post–distortional buckling on both local and distortional buckling are also examined.