Computational prediction of the lifetime of self-healing CMC structures

Self-healing Ceramic-Matrix Composites (CMCs) are good candidates for structural applications at high temperatures in oxidizing environments. These materials generate complex couplings between the thermal and mechanical fields. A multiphysics macroscopic model of both the mechanical behavior and the lifetime of CMC structures was proposed previously and was validated on the material's level. Here its effectiveness in dealing with structural calculations with heterogeneous fields is analyzed and a nonlocal fracture criterion is proposed for high-gradient cases. All the simulations were carried out using Abaqus/Standard. The main interest of the model is its ability to predict the evolution of each of the material's mechanisms throughout the structure until final fracture. Another advantage is the ability to predict the fracture zone and the influence of indentations on the lifetime of the structure (damage tolerance analysis), both of which are very important for industrial developments. (C) 2011 Elsevier Ltd. All rights reserved.