An Approach for Mechanistic Modeling of Ceramic Matrix Composites

A mechanistic modeling approach for material characterization and for life prediction of CMC components is described. The approach includes consideration of environment-induced degradation of CMC properties, progressive microcracking of the matrix material and interfacial damage. The mechanistic model has been embedded in a finite element analysis (FEA) framework to enable structural analyses of components and to analyze macro damage, such as cracks and delaminations. This paper describes the modeling approach and its application in the study of substructures. Examples include analyses of simple test specimen coupons, stress concentration at holes and a structural element configuration of a 2D woven SiC/SiC composite. The results include predicted and measured strain field near circular holes and global load-displacement behavior of structural elements. In each case, the model predictions are compared with the experimental measurements.