An innovative micromechanics-based multiscale damage model of 3D woven composites incorporating probabilistic fiber strength distribution

An innovative micromechanics-based multiscale damage model for investigating the complex failure behaviors of 3D woven composites is proposed in this paper. The microscale and mesoscale representative volume cells (RVC) are established to sequentially define the fiber arrangements within yarns and the intertwined yarn architecture of realistic composites. The micromechanics of failure criteria (MMF) are adopted to identify the damage initiations of fibers and matrix constituents, and the damage evolvements are governed by the equivalent displacements and fracture toughnesses to alleviate the mesh dependency. The loading direction effects on the stress distributions of micro RVC with hexagonal fiber arrangements are studied by conducting a suite of micromechanics analyses. Instead of using deterministic values, the stochastic strengths of fiber filaments are characterized by adopting a Weibull probabilistic distribution. Particularly, the influences of fiber strength distributions on the performance of woven composites are parametrically investigated. The proposed multiscale damage model is integrated to ABAQUS with a user-defined subroutine to analyze the quasi-static damage responses of 3D woven composites. The numerical predictions exhibit a good correlation with the relevant experiments.