Micromechanical modeling of ductile damage of polycrystalline materials with heterogeneous particles

A two-level homogenization approach is applied in this micro-mechanical modeling of the ductile damage of polycrystals containing intracrystalline non-shearable particles. Voids nucleate around these second phase particles by interface debonding and thereafter, grow due to the plastic straining of the crystalline matrix. The equivalent behavior of the single crystal containing voids is derived from the description of the single crystal with particles. Moreover, this behavior is deduced from the classical formulation of the single crystal plasticity based on crystallographic gliding and Schmidʹs law. At microscopic scale, void nucleation is possible when the elastic strain energy stored in the particle and released during debonding exceeds the energy of creation of new surfaces at the crystal-particle interface. The material pre-damage behavior is described by the hardening by intra-crystalline particles model proposed in Bonfoh et al. (2003).