A coupled thermal-mechanical-oxidative model for predicting oxidation and stress affected by cracks

Abstract

High-temperature thermal structural materials under laser irradiation are often exposed to simultaneous thermal stresses and mechanical loads, and the interaction between these factors may lead to crack propagation, oxide delamination, and even material failure. By establishing a novel coupled thermal-mechanical-oxidative (CTMO) model, this study systematically investigates the effects of crack properties on the oxidation growth and stress evolution of C/SiC composites in a high-temperature-stress-oxidative environment. Unlike the existing studies, this study incorporates several crack characterization parameters, such as crack width, spacing, depth, and inclination angle, into a unified multi-physics field coupling framework. The complex effects of these parameters on oxide formation and stress distribution are analyzed in detail. Through numerical simulations, this paper reveals the interaction mechanism between mechanical loading, oxidation behavior and crack evolution, especially the material degradation behavior under extreme conditions. The results show that the crack width and depth significantly affect the oxide diffusion and stress concentration, while the crack spacing and inclination angle further influence the material failure mode by changing the stress field interactions and oxidant diffusion paths. The CTMO model proposed not only provides theoretical support for the optimization of the performance of high-temperature thermal structural materials in complex environments, but also provides a scientific basis for the material selection and design optimization of laser protection systems. The results reveal the coupling effect between oxide growth and crack extension, which provides a new perspective for understanding the degradation mechanism of composite materials under high-temperature stress oxidation environment.