Distortional buckling of stiffened cold-formed steel channel sections.

This paper is concerned with distortional buckling of cold-formed steel channel sections by the semi-analytical complex finite strip method. The main purpose of this paper is to study the buckling behavior of cold-formed channel sections with extra longitudinal stiffeners at the end of flanges and also on the web. One of the most important purposes of this study is to investigate the optimum width of extra longitudinal flange stiffeners in cold-formed channel sections. Furthermore, the optimum position of longitudinal web stiffeners is calculated to maximize the distortional as well as local buckling strength of cold-formed channel sections. For validation purposes, complex finite strip method results are compared with those obtained by Generalized Beam Theory (GBT) analysis. Using the semi-analytical complex finite strip method, a comparison on the buckling behavior of unstiffened and stiffened cold-formed channel sections in local, distortional and global modes will be done.