Three-stage full-range stress-strain model for stainless steels

Advanced numerical modeling of cold-formed stainless steel members, from manufacturing to full-range response under applied loading, requires knowledge of the stress-strain relationship of the material over a wide range of tensile and compressive strains. Although a number of stress-strain models have been developed for stainless steels, they are only capable of accurate predictions either over a limited strain range or for the tensile stress-strain behavior only. This paper presents a three-stage stress-strain model for stainless steels, which is capable of accurate predictions over the full ranges of both tensile and compressive strains. The new stress-strain model is defined using the three basic Ramberg-Osgood parameters and is based on a careful interpretation of existing experimental data. The accuracy of the proposed model is demonstrated by comparing its predictions with experimental stress-strain curves. These comparisons also clearly demonstrate the advantage of the proposed model over the only existing full-range stress-strain model.