On the description of large plastic deformations in dual-phase steels

In this work we present a new version of large deformation generalized plasticity which accounts for the constitutive modeling of dual phase steels. The formulation is presented in a general format by leaving both the rate equations for the evolution of the internal variables and the kinematics of the deformation unspecified. As an application, on the basis of the multiplicative decomposition of the deformation gradient into elastic and plastic parts and the use of a hyperelastic constitutive equation, we propose a rather simple material model. We also present standard numerical examples, where special emphasis is placed on the description of the complex phenomena of yield stress reduction (Bauschinger effect), rapid transient strain hardening and long term (permanent) softening, which appear in a typical loading-unloading-reloading stress-strain curve.