Experimental evaluation of DSM beam-column strength of cold-formed steel members under uniaxial eccentric compression

摘要

In this paper, the direct strength method (DSM) design of cold-formed steel (CFS) beam-column is evaluated using the results of controlled experiments. The experimental setup is devised to create a uniform moment along the member length about both the major and the minor axes of the member. A comparison of code provisions of AISI S100-2016 for CFS beam-column design against twenty-two experiments reveals a disagreement when the failure mode is due to an interaction of distortional-flexural torsional (D+FTB) buckling. The study proposes a modification to the linear interaction framework (LI) and nonlinear interaction (NLI) framework to include the distortional-global (D-G) interaction. These modifications have been demonstrated to result in strength predictions that are closer to the experimental evidence.