  We address the prediction of ductile damage and material anisotropy
accumulated during plastic deformation of metals. A new model of
phenomenological metal plasticity is proposed which is suitable for
applications involving large deformations of workpiece material. The model
takes combined nonlinear isotropic/kinematic hardening, strain-driven damage
and rate-dependence of the stress response into account. Within this model, the
work hardening and the damage evolution are fully coupled. The description of
the kinematics is based on the double multiplicative decomposition of the
deformation gradient proposed by Lion. An additional multiplicative
decomposition is introduced in order to account for the damage-induced volume
increase of the material. The model is formulated in a thermodynamically
admissible manner. Within a simple example of the proposed framework, the
material porosity is adopted as a rough measure of damage.
  A new simple void nucleation rule is formulated based on the consideration of
various nucleation mechanisms. In particular, this rule is suitable for
materials which exhibit a higher void nucleation rate under torsion than in
case of tension.
  The material model is implemented into the FEM code Abaqus and a simulation
of a deep drawing process is presented. The robustness of the algorithm and the
performance of the formulation is demonstrated.
