A micromechanical model for thermostructural composites

A damage model based on a micromechanical approach was studied in order to predict damage development in ceramic-matrix composites under thermomechanical loading conditions. Complex damage phenomena like matrix microcracking, fibre or bundle debonding and fibre breakage can occur. All these mechanisms can be modelled at the microscopic scale. Thus, correlation between the different scales and reliable homogenization procedures have been developed. This micro-macro model is applied to various SiC/SiC and a C/SiC composites. By the use of this model, the intrinsic mechanical properties of the classical CVI SiC matrix have been identified. Implementation of this model was done by means of the finite-element code ABAQUS. An application was carried out on a notched specimen made of Cerasep® N3-1 composite.