A Nonequilibrium Thermodynamics-Based Model to Predict Fatigue Failure in Particle-Reinforced Metal Matrix Composites

Abstract

The presented fatigue crack growth (FCG) life prediction model for particle-reinforced metal matrix composites (MMCs) leverages nonequilibrium thermodynamics to characterize the life cycle of crack growth. The model uses an energy balance approach to evaluate FCG rates, focusing on the specific dissipated plastic energy per unit area within the cyclic plastic zone (CPZ), quantified as the area under the cyclic stress–strain curve. The model includes microstructural parameters through strengthening mechanisms, enhancing the model's accuracy. The closed-form analytical solution shows strong alignment with the experimental data across various particle-reinforced MMCs, thereby providing reliable FCG life predictions. The key microstructural parameters, including strain amplitude, hardening exponent, strength coefficient, and particle volume fraction, affect the fatigue life and crack propagation resistance. Polar plots of strain amplitude variations further provide insight into the crack propagation around the CPZ, highlighting the influence of microstructural parameters on crack growth.