Experimental study on cold-formed steel built-up section beam-columns experiencing non-uniform bending

The experimental study presented in this paper aimed to examine the performance of cold-formed steel built-up section beam-columns experiencing non-uniform bending. test program was performed on open and closed sections that were manufactured from grades G500 G550 zinc-coated sheets. specimens assembled by connecting two identical channels with discrete connectors along longitudinal direction. Two member lengths plate thicknesses considered for investigate stability newly designed thin-walled beam-columns. In total, thirty-five beam-column tests carried out under pinned supports. results including loading capacity, failure mode axial load-lateral deflection response obtained are fully reported paper. Moreover, comparison capacities nominal strengths conducted evaluate applicability interaction curves specified North American Specification AISI S100, Australian/New Zealand Standard AS/NZS 4600, European Code EN 1993–1-1 ANSI/AISC 360 bending compression resistances calculated direct strength method members moment gradients. Overall, these design methods conservative predictions unequal end moments. For synchronous compression, aforementioned generally offered slightly predictions, except interactive formula determined method.