Combined simulation of quasi-static deep drawing and electromagnetic forming by means of a coupled damage–viscoplasticity model at finite strains

Abstract

The combination of quasi-static and electromagnetic pulse forming increases the formability of sheet metal forming processes. A cooperation between the institute of Applied Mechanics (IFAM) of the RWTH Aachen and the Institute of Forming Technology and Lightweight Construction (IUL) of the TU Dortmund is investigating these processes both experimentally and by simulation for the deep-drawing process of a cross-shaped cup. Aim of the work is to show and prove that with this forming strategy we obtain a more sharpened radius of the cup edges.The combined deformation process is simulated by means of finite elements using a material model developed in [1,2]. A recently proposed finite strain anisotropic viscoplastic model, taking combined nonlinear kinematic and isotropic hardening into account, is coupled with ductile damage in the context of continuum damage mechanics. For the simulation, the evolution equations for the internal variables of the constitutive model are numerically integrated in an explicit manner and the model is then implemented as a user material subroutine in the commercial finite element package LS-Dyna.