Local buckling and capacity of press-braked ferritic stainless steel channel sections under minor-axis combined loading

Abstract

This paper presents experimental and numerical studies of the local buckling behaviour and cross-section resistances of press-braked ferritic stainless steel channel sections under combined compression and minor-axis bending. An experimental programme was firstly conducted and included material testing, initial local geometric imperfection measurements and ten eccentric compression tests. Following the experimental programme, a numerical modelling programme was conducted, where finite element models were developed to replicate the test observations and then used to perform parametric studies to generate further numerical data over a wide range of cross-section dimensions and loading combinations. The obtained test and numerical data were then used to assess the relevant design interaction curves for press-braked ferritic stainless steel channel sections under minor-axis combined loading, as set out in the European code and American specification. The assessment results revealed that the codified design interaction curves result in conservative and scattered resistance predictions, mainly owing to the conservative bending end point and inefficient linear shape. Finally, new design interaction curves were developed and shown to provide a higher level of design accuracy and consistency than the codified design interaction curves.