Cold-formed ferritic stainless steel tubular structural members subjected to concentrated bearing loads

The behaviour and design of cold-formed ferritic stainless steel tubular structural members subjected to concentrated bearing loads are presented in this paper. A total of 37 web crippling tests was conducted on cold-formed square and rectangular hollow sections of grade EN 1.4003 ferritic stainless steel. The tests were conducted under end loading and interior loading conditions, which closely simulated the support conditions of floor joist members seated on solid foundation. Finite element (FE) models were developed and validated against the experimental results. Upon validation of the FE models, a parametric study comprised 160 FE analyses was performed using the validated models. The web crippling strengths obtained from experimental and numerical investigations were compared with the nominal strengths calculated using the current American, Australian/New Zealand and European specifications for stainless steel structures. Furthermore, the North American Specification (NAS) and the Australian Standard AS4100 for carbon steel structures as well as the suggested design rules in the literature for stainless steel structures were also compared. Improved design rules are proposed for ferritic stainless steel tubular structural members subjected to concentrated bearing loads by means of modified NAS and Direct Strength Method. The reliability of the proposed design rules has been assessed through reliability analysis.