Modelling void nucleation and growth processes in a particle-reinforced metal matrix composite material

Abstract

The nucleation and growth of voids in a particle-reinforced metal matrix composite (MMC) material have been modelled using internal state variable equations implemented in a unit-cell finite element model. The coupled elastic-viscoplastic damage constitutive equations enable a good representation of the dependence of the stress-strain behaviour on particle volume fraction, the influence of the damage process on the stress-strain behaviour, and the nature of the damage evolution over a range of volume fraction of particles. In particular, the volume fraction of reinforcement in the MMC material is found to influence the nature of the damage evolution process, and a volume fraction of approximately 20% has been identified as separating two different modes of damage evolution.