Numerical Simulation of an Hexnut Forming Process Including Damage Effect
This article deals with numerical simulation of an hexnut forming process including the ductile damage occurrence in the framework of the Continuum Damage Mechanics (CDM). In this paper, fully coupled constitutive equations accounting for both the isotropic hardening and the ductile damage are implemented into the industrial FE codes Forge2 and Forge3 . First, the theoretical formulation of the coupled constitutive equations in the framework of CDM is presented. The numerical aspects are then presented and discussed using an implicit integration schemes for the local time integration of the coupled constitutive equations and a static implicit scheme to solve the associated initial and boundary value problem. This gives a very useful numerical tool able to predict where and when a significant ductile damage will occur in the part during the forming process. Hence, we are able to modify some pertinent process parameters to avoid the damage occurence in order to obtain an undamaged part as in deep drawing, forging and so on. On the other hand, we can look to enhance the damage initiation and propagation, typically for the simulation of any stamping or cutting processes.
Jean-François MARIAGE, Khémaïs SAANOUNI, Philippe LESTRIEZ, Abdelhakim CHEROUAT
thermo-elasto(visco)plasticity, ductile damage, numerical methods, finite elements, virtual metal forming, hexnut.