Phase‐field modeling of crack growth and interface sliding in ceramic matrix composites

Abstract Fiber‐reinforced ceramic matrix composites (CMCs) are used in structural components of gas turbines and fusion reactors due to their high toughness and ability to withstand ultra‐high temperatures. The enhanced fracture toughness of CMCs arises from the complex interactions between mechanical damage and their microstructures that involve fiber bridging, fiber pull‐out, crack deflection, and sliding at the fiber‐matrix interfaces. However, there is a lack of microstructure‐resolved models that enable direct simulation of these damage processes. This study introduces a phase‐field model that explicitly accounts for microstructure‐level cracking and interface sliding in CMCs. Simulations are performed to investigate the effects of fiber diameter, orientation, length, density, and interface sliding resistance. Fiber bridging and fiber pull‐out are successfully simulated. In particular, the simulation results demonstrate the critical role of interface sliding in fiber bridging. Parametric studies suggest that thicker fibers, longer fibers, and lower interface sliding resistance can lead to enhanced performance of CMCs when fiber bridging dominates the damage processes. This model has demonstrated its capability to serve as a valuable tool for quantitative understanding of CMC damage processes and for guiding design of the microstructures for next‐generation CMCs.