Ductile damage micromodeling by particles’ debonding in metal matrix composites

The elastic–plastic behaviour of particle-reinforced metal matrix composites undergoing ductile damage is modelled using a two-level micro-structural approach. The considered heterogeneous material is a polycrystal containing intra-crystalline elastic particles. Ductile damage is initiated by the matrix/particle interface debonding and the subsequent voids growth with plastic straining of the crystalline matrix. Homogenization techniques are used twice: first at mesoscale to derive the equivalent grain behaviour and then to obtain the macroscopic behaviour of the material. Plastic deformation of the crystalline matrix is due to crystallographic gliding on geometrically well-defined slip systems. The associative plastic flow rule and the hardening law are described on the slip system level. The evolution of micro-voids volume fraction is related to the plastic strain. The elastic–plastic stress–strain response of particle composite is investigated. Predictions of the proposed model are compared to experimental data to illustrate the capability of the suggested method to represent material behaviour. Furthermore, specific aspects such as the stress triaxiality and yield surfaces are discussed.