Ultimate capacity of stainless steel RHS subjected to combined compression and bending

To maintain consistency with carbon steel design guidance, the current European design code for stainless steel structures EN 1993-1-4 employs many of the relevant design expressions from the equivalent carbon steel design code EN 1993-1-1. While this is generally satisfactory, there are a number of instances in which overly conservative designs result. Given the high initial material cost of stainless steel, the derivation of more economic design expressions in accordance with the actual material response is warranted. To this end, the Continuous Strength Method (CSM) has been developed and verified against experimental and numerical results. To date, the scope of the CSM has been restricted to stainless steel cross-sections subjected to compression or uniaxial bending. The present paper aims to extend the scope of application of the CSM to cross-sections subjected to more general loading conditions likely to occur in practice. Furthermore, a simplified version of the CSM, with a more straightforward base curve and material model, but still capturing the essential strain hardening features of stainless steel, is considered. The comparisons show that the simplifications lead to very little loss of accuracy and will be developed further in future studies.