3D numerical simulation of anisotropic thin sheet metal slitting process using fully coupled constitutive equations including ductile damage

Abstract

In this work, an anisotropic plastic constitutive equation accounting for both isotropic and kinematic hardening fully coupled with isotropic ductile damage is presented from both theoretical and numerical standpoints. A radial return algorithm applied to a reduced number of constitutive equations is used in order to compute the stress tensor as well as all the internal variables at the end of time steps. The proposed model is implemented into ABAQUS/EXPLICIT FE code using the Vumat user’s subroutine and the resultant initial and boundary value problem is solved thanks to the classical Dynamic Explicit scheme. Application is made to slitting of 3D anisotropic sheet by studying the influence of some process parameters as the shape of the knives, the sheet thickness and the initial residual stress fields. The proposed methodology is shown to be very useful and helpful when dealing with a “virtual” improvement of any slitting process.