CALCULATION OF THE ELASTIC DISTORTIONAL BUCKLING FOR COLD-FORMED THIN-WALLED CHANNEL COLUMNS WITH INCLINED SIMPLE EDGE STIFFENERS UNDER AXIAL PRESSURE

The Distortional buckling is an important buckling mode governing the stability design of cold-formed lipped channel columns. The elastic distortional critical stress is the key point for the distortional buckling calculation according to current main design codes and specifications. The explicit formulae for the longitudinal warping displacement calculation of members in a distortional buckling mode are derived. And the calculation course is simplified. Based on the classical plate theory, the formulae of in-plane displacements are deduced. And the plane deformation of a cross-section is thusly determined. On the base of the existing research results, the formulae of the elastic distortional buckling for cold-formed thin-walled channel columns with inclined simple edge stiffeners under axial pressure are presented. The presented formulae predict good results, compared with the finite strip method and approximation model method. The results demonstrate the validity and efficiency of the method presented in this paper. Being simply and usable, it is a manual method which can give reference to the research and design.