Cold-Formed Steel Channel Sections with Web Stiffeners Subjected to Local and Distortional Buckling — Part II: Parametric Study and Design Rule

A parametric study of cold-formed steel channel sections with web stiffeners subjected to bending was performed using finite element analysis (FEA).An accurate finite element model was used for the parametric study.The parametric study included 75 beams of plain and lipped channel sections with web stiffeners.The beams were simply supported and subjected to four-point bending.The strengths and failure modes of specimens obtained from experimental and FEA results were compared with design strengths predicted using the direct strength method (DSM) specified in the North American Specification for cold-formed steel structures.The comparison shows that the design strengths predicted by the current DSM are conservative for both local buckling and distortional buckling in this study.Hence, the DSM is modified to cover the new stiffened channel sections investigated in this study.A reliability analysis was also performed to assess the current and modified DSM.