Local–flexural interactive buckling behaviour and design of press-braked stainless steel slender Z-section columns

Abstract

The present paper reports an experimental and numerical study on the local–flexural interactive buckling behaviour and resistances of press-braked stainless steel slender Z-section columns. A testing programme adopted two press-braked stainless steel slender Z-sections and included material testing, initial geometric imperfection measurements and twelve fixed-ended column tests, with the experimental setups, procedures and results fully reported. The testing programme was accompanied by a numerical modelling programme, with finite element models developed and validated against the fixed-ended column test results; upon validation, parametric studies were conducted to generate additional numerical data over a wide range of cross-section dimensions and member lengths. The obtained test and numerical data were adopted to evaluate the relevant design rules for press-braked stainless steel slender Z-section columns susceptible to local–flexural interactive buckling, as set out in the American specification and European code. It was revealed from the evaluation results that the American specification led to accurate interactive buckling resistance predictions, while the European code resulted in relatively conservative interactive buckling resistance predictions. Finally, a revised Eurocode design approach was developed and provided more accurate and consistent interactive buckling resistance predictions for press-braked stainless steel slender Z-section columns than its original counterpart.