Testing, simulation and design of press-braked ferritic stainless steel slender channel section columns failing by local–flexural interactive buckling

Abstract

This paper presents an experimental and numerical study of the local–flexural interactive buckling behaviour and resistances of press-braked ferritic stainless steel slender channel section columns. An experimental programme was firstly conducted, including initial geometric imperfection measurements and ten pin-ended column tests. Interaction between local buckling and flexural buckling was observed for all column specimens upon testing and discussed in detail. The test results were used in a parallel numerical modelling programme to validate finite element models, which were then adopted to perform parametric studies to generate additional numerical data over a wide range of cross-section dimensions and member effective lengths. Based on the test and numerical data, the relevant design rules for press-braked ferritic stainless steel slender channel section columns, as given in the American specification and European code, were evaluated. The evaluation results revealed that the American specification resulted in a good level of design accuracy, while the European code led to conservative and scattered interactive buckling resistance predictions. Finally, a revised Eurocode design method was proposed and shown to yield much more accurate and consistent interactive buckling resistance predictions for press-braked ferritic stainless steel slender channel section columns than its original counterpart.