FINITE ELEMENT ANALYSIS RESEARCH ON BUCKLING BEHAVIOUR OF UNRESTRAINED STIFFENED COLD FORMED STEEL CHANNEL AND ZED SECTIONS

This research mainly concentrates on ultimate strength and buckling behaviour of CFS laterally un-braced longitudinally stiffened Channel (C) and Zed (Z) sections under flexure. A total ten various stiffener combinations for C and Z sections has been studied by modifying the shape of a simple end stiffened section by the provision of intermediate stiffeners along web, flange or both along web and flange. The influence of different types of stiffeners with respect to various aspect radio’s (H/T, B/T, C/T and H/B) have been studied using Finite Element Method (FEM), Direct Strength Method (DSM) and Indian Standard Method (IS) and recommendations have been proposed on provisions of different types stiffeners and design standards. In summary, in view of the increase in buckling strength of open C and Z flexural members, provision of V shape intermediate stiffeners along the web and flange has been proposed.