Time-Dependent Deformation and Damage Modeling of a SiC/SiC Composite

Time-dependent elevated temperature behavior of a two-dimensional (2D) woven melt-infiltrated Sylramic (SiC) ceramic matrix composite (CMC) is investigated. A micromechanics-based model that includes consideration of matrix and interfacial damage and of creep/relaxation of the matrix is used. The model also accounts for composite fabrication process induced residual stress in the constituents and load transfer between the constituents due to damage and creep. Test data from undirectionally loaded specimens are used to obtain values of all relevant material properties and damage parameters. Next, the model is used with the finite-element method to predict time-dependent behavior under multiaxial stresses and stress concentrations. Predictions are compared with measurements including postcreep stress-strain response in specimens with and without holes.