Cold-Formed High-Strength Steel Tubular Structural Members under Combined Bending and Bearing

This paper presents experimental and numerical investigations of cold-formed high-strength steel (CFHSS) tubular structural members under combined bending and bearing. A test program that contained 33 experiments was undertaken on square hollow sections (SHSs) and rectangular hollow sections (RHSs) with nominal yield strengths up to 900 MPa. The combined bending and bearing experiments were performed under the interior-one-flange bearing load case as per the North American Specification (NAS). Finite-element models were built and validated with the experiments; a parametric study was undertaken upon validation. The experimentally and numerically obtained results were compared with nominal resistances as per the NAS and European Code (EC3) to examine their applicability to CFHSS SHS/RHS members under combined bending and bearing. Overall, the comparisons reveal that the NAS provisions were generally conservative whereas the EC3 provisions were overly conservative. It is shown that the codified bending and bearing interaction formulas can be used for CFHSS SHS/RHS members, while more accurate predictions can be achieved using recently proposed bearing design rules.