A 3D constitutive model of high-strength constructional steels with ductile fracture

Abstract

In order to describe and predict cyclic behavior of HSS steels under triaxial stress states, a new cyclic constitutive model with consideration of damage accumulation and influence of triaxial stress states based on ductile fracture model is formulated to simulate the response of HSS steels subjected to a range of loading types in terms of triaxial stress state and loading histories. The model, termed as HSS-3D, is supported by an experimental program consisting of coupon scale monotonic and cyclic tests. The HSS-3D model proposed is able to simulate: (1) the Lode angle dependence through an enhanced yield function which modifies the conventional von Mises yield surface; (2) the deterioration of the elastic region at high accumulated strains through new isotropic softening relationship; (3) the influence of stress states on strength softening behavior of HSS steels and (4) ductile fracture of steels under cyclic loading.