Behaviour of stainless steel plain channel section columns

In this paper, the structural stability of cold-formed stainless steel plain channel columns under axial compression is investigated. Reliable finite element models for channel section columns are first developed and validated against experiments conducted on stainless steel lipped channel specimens. This is followed by a parametric study in which columns made of austenitic, ferritic and duplex stainless steel are assessed. The considered cross-section classes and column lengths cover the entire range of global slenderness. The effects of material and geometrical nonlinearity are considered in the numerical analysis. The numerically generated data are then employed to evaluate the accuracy of the current European and Australian design codes EN 1993-1-4 and AS/NZS 4673 respectively, for predicting the flexural and flexural-torsional column buckling resistance. The results show a necessity to improve the current buckling curve used to predict the flexural buckling resistance of plain channel section columns, currently adopted in EN 1993-1-4, whose use may lead to unsafe predictions, especially for the austenitic grade.