Research on Failure Behavior of Metal Matrix Composites Based on Phase Field Method and Cohesive Zone Model

Abstract

The failure mechanisms of metal matrix composites (MMCs) under extreme environments such as high temperature and high strain rates are key issues restricting their reliable application. This paper develops a thermo-mechanical-rate coupled phase field-cohesive zone model to simulate the synergistic failure behavior of their matrix and interface. By introducing a temperature degree of freedom and rate-dependent functions, the model achieves dynamic evolution of cohesive strength and fracture energy with temperature and strain rate. The results show that the rate parameters ζ₁ and ζ₂ significantly affect the cohesive strength and failure displacement, respectively, while the temperature parameters κ_T and ϛ_T dominate the thermal softening effect and fracture energy degradation. Obvious competition among failure modes is observed under different working conditions: high strain rates promote increased cohesive strength and particle fracture, while high temperatures lead to strength softening and interface debonding dominance. This model provides an effective analysis tool and theoretical basis for revealing the damage mechanisms of multiphase materials under thermo-mechanical coupled loads.