Axial compression behavior and design method of SCBS cold-formed SHS stub columns

This study investigates the local buckling behavior and design of press-braked square hollow section (SHS) stub columns fabricated from stainless-clad bimetallic steel (SCBS) through experimental and numerical approaches. Axial compression tests were conducted on five stub column specimens manufactured from hot-rolled SCBS plates with nominal thicknesses of 5 mm, 4 mm, and 3 mm, considering varying clad ratios and width-to-thickness ratios. A finite element (FE) model was developed and validated against test results, followed by a comprehensive parametric study examining the influence of clad ratio and normalized plate slenderness. The applicability of existing design specifications to SCBS SHS stub columns was assessed by comparing their predictions with numerical results. Based on the parametric analysis and evaluation of current design methods, a normalized plate slenderness limit and an Effective Width Method formula are proposed. The proposed design approach offers improved efficiency and consistency, providing a reliable basis for the application of cold-formed SCBS columns in structural engineering.