Buckling Curves for Cold-Formed Stainless-Steel Columns and Beams

This paper summarizes the background information and methodology used to derive a set of buckling curves proposed for cold-formed stainless steel columns and beams incorporated in the recently revised SEI/ASCE 8-21 Specification. The study is based on experimental and numerical data collected from the literature on cold-formed stainless steel columns and beams featuring ASTM grades 304, 2101, 430, 404, and 443. Because most of the investigated specimens exhibited slender cross-sections, both the effective width method (EWM) and the direct strength method (DSM) are considered to account for the effect of interaction between global and local buckling on member strength. Buckling curves for flexural buckling and lateral-torsional buckling codified in current international standards are assessed based on the SEI/ASCE 8 reliability requirements, and new curves are derived accordingly. The proposed new buckling curves include expressions to account for the postyielding capacity of stainless steel columns and the inelastic buckling resistance of cold-formed stainless steel beams. In addition, a new local buckling strength curve for members in flexure is proposed in the format of the DSM and shown to provide equivalent design resistances to the EWM.