Experimental investigations on plain channels in coupled instabilities

This paper presents experimental investigations on thin-walled steel members with C-cross sections subjected to both local and global buckling failure. Different cross sections, buckling length and steel grades have been investigated for welded and cold-formed sections. Experimental tests on stub columns with only local buckling failure and on longer columns with combined local and global buckling will be presented. The stub column tests focused on the local buckling mechanisms with respect to axial compression loading and combined compression and bending. By testing longer columns subjected to both local and global buckling, the interaction of local and global buckling failure will be addressed. Therefore results will be based on general observations from the local buckling stub column tests. The influence of initial global geometric imperfections with respect to size and shape will be identified as crucial for the overall ultimate buckling strength of C-sections subjected to coupled instabilities.