Fatigue Crack Propagation Analysis of Continuous Fiber‐Reinforced Titanium Matrix Composites Considering Fiber Bridging Based on XFEM

ABSTRACT Fiber‐reinforced titanium matrix composites (TMCs) possess high specific strength and stiffness, making them attractive for load‐bearing structural components in aerospace and other advanced engineering applications. However, under cyclic loading, fatigue failure becomes a critical concern, where fiber bridging frequently occurs during crack propagation and significantly influences fatigue resistance. Despite its importance, existing models rarely capture the effect of fiber bridging on fatigue crack growth, resulting in an incomplete understanding of fatigue behavior in composites. To address this issue, this study develops a fatigue analysis model based on the extended finite element method (XFEM), incorporating a bridging law to describe the shielding effect of fiber bridging at the crack tip. The model fully exploits the advantage of XFEM in simulating crack propagation without remeshing and integrates a Weibull‐based random fiber strength distribution to account for stochastic fiber fracture. Analysis results demonstrate that the proposed model can accurately reproduce the dual effects of fiber bridging and random fiber breakage on fatigue crack growth behavior, while providing reliable fatigue life predictions for TMCs. At stress ratios of 0.1 and 0.3, the predicted fatigue life errors are only 2.81% and 2.88%, respectively. This work provides a necessary and effective modeling framework for understanding fatigue mechanisms in TMCs and offers practical guidance for their reliable application in service‐critical environments.