Computational study of micromechanical damage behavior in continuous fiber-reinforced ceramic composites

摘要

A comprehensive numerical analysis of micromechanical damage behavior in a continuous fiber-reinforced ceramic composite is presented. A three-dimensional micromechanical finite element modeling procedure is developed for effective elastic property estimation and damage evaluation by the example of a composite consisting of a silicon carbide matrix unidirectionally reinforced with silicon carbide fiber (SiC/SiCf). The effect of a fiber/matrix interface on predicted elastic properties of the SiC/SiCf composite is considered. Representative volume element (RVE) models are developed for an SiC/SiCf composite with damageable interfaces. Statistically equivalent RVE models with randomly distributed fibers are generated using a developed algorithm. The statistical variability of fiber and matrix strengths is considered in developing RVE models and assumed to follow a Weibull probability law. A user-material subroutine with an adaptive material constitutive law is developed to predict damage behavior in the RVE. The predicted uniaxial stress versus strain behavior and damage in the composite are discussed.