Cross-sectional behaviour and design of ferritic and duplex stainless steel EHS in compression

This paper describes an investigation into the cross-sectional behaviour of elliptical hollow section (EHS) columns made from ferritic and duplex stainless steel. The EHS is a relatively new structural shape with a number of favourable attributes including aesthetic appeal, high strength-to-weight ratio, good torsional resistance and excellent flexural strength. In recent years there have been significant developments in the analysis and understanding of these shapes, although most studies have focused on carbon steel EHS. The work so far is taken a step further here by considering some of the newer grades of stainless steel that are used in structural applications. A numerical model is developed and validated against test data from the literature and is then employed to generate structural performance data. Subsequently, parametric studies are performed to investigate the influence of individual parameters such as the material properties, aspect ratio and local slenderness of cross-sectional elements. The accuracy of existing design procedures is assessed by comparing the numerical data with the resistances obtained using Eurocode 3. It is shown that the cross-sectional slenderness limits given in Eurocode 3 for EHS members made from carbon steel can also be safely used for sections made from ferritic and duplex stainless steel.