| Abstract Scope |
CMCs are used for structural parts in gas turbines and fusion reactors due to its high toughness and ability to endure ultra-high temperatures. The mechanism of the enhanced fracture toughness of CMCs lies in the interaction between the crack growth and the microstructure, which involves fiber bridging and sliding of the fiber-matrix interfaces. However, there is a lack of microstructure-resolved models that enable the direct simulations of crack growth and interface sliding. This study introduces a phase-field model which incorporates the CMC microstructures, matrix cracking, fiber breakage, and interface sliding. The model can simulate fiber bridging, validated by experimental observations in the literature. Simulations are performed to investigate the influences of fiber thickness, orientation, length, and density, and interfacial sliding resistance. Simulation results suggest optimal parameters for enhanced toughness of CMCs. This model could serve as a powerful tool for designing microstructures for next-generation CMCs. |