Direct strength method for the shear design of cold-formed stainless-steel sections

A unified Direct Strength Method (DSM) shear design framework for cold-formed stainless steel (CFSS) lipped channel sections, applicable to members without and with web holes, is presented herein. Despite the growing use of CFSS members, no codified DSM based shear design provisions currently exist for this material, and the specific case of CFSS sections with web holes has not previously been addressed in the literature. A database comprising 8 experimental results and 278 validated finite element results was assembled from the literature. No experimental shear tests are currently available in the literature for CFSS lipped channel sections with circular web holes. The applicability of existing equations for yield shear load and elastic shear buckling load to CFSS sections, including modifications to account for the presence of web holes, was evaluated systematically, and suitable adaptations are proposed. A continuous-format DSM shear design curve, consistent with the framework proposed by Glauz and subsequently adopted in ANSI/SDI AISI S100:2024, was calibrated and assessed against the assembled database. The proposed unified curve treats webs without and with web holes within a consistent design philosophy, eliminating the need for separate provisions. The proposed DSM shear design framework provides accurate and reliable predictions of the nominal shear capacity of CFSS lipped channel sections, with a mean test/FE-to-prediction ratio of 1.00 and a COV of 0.056, thereby providing a rational starting point for the future development and experimental validation of unified DSM-based shear design provisions for CFSS members.