Modeling of temperature-dependent first matrix cracking stress in ceramic matrix composites considering fracture surface energy and residual thermal stress

Ceramic matrix composites have shown excellent performance in fields such as hypersonic vehicles, and their matrix cracking stress is an important criterion for determining whether damage has occurred in composites, but obtaining the first matrix cracking stress at elevated temperatures is very difficult. In this study, a temperaturedependent theoretical model of first matrix cracking stress considering fracture surface energy and residual thermal stress for ceramic matrix composites was developed based on the Force-Heat Equivalence Energy Density Principle. The model successfully captures the quantitative relationship between the first matrix cracking stress and parameters such as temperature and Young's modulus. Without the need to carry out any high-temperature destructive experiments, the developed model can easily predict the temperature-dependent first matrix cracking stresses of the material. The validation shows that the model predictions achieve good agreement with the experimental data at different temperatures (from 293K to 1673K), and the predictions of the developed model have higher accuracy compared to the two commonly used theoretical models. In addition, the effect of fracture surface energy on matrix cracking stress at different temperatures was quantitatively analyzed. The research results provide a non-destructive method for obtaining the first matrix cracking stress of materials at elevated temperatures.