Local buckling resistances of cold-formed high-strength steel SHS and RHS with varying corner radius

This paper reports an experimental and numerical study of the cross-sectional behaviour of cold-formed high-strength steel (HSS) square and rectangular hollow section (SHS and RHS) members. Six stub column tests, six 3-point and three 4-point bending tests have been carried out, followed by the development of accurate finite element (FE) models and a parametric study. Based on the test and FE results, the design rules for slender cross-sections in European, American, Australian and Chinese standards and the GSRM method have been assessed via reliability analyses. A new equation for deriving the cross-sectional slenderness of SHS and RHS considering the influence of corner radius and new area reduction factors for designing slender cold-formed S900 (and above) SHS and RHS have also been propose