A Thermo-mechanical-oxidation-diffusion Coupled Peridynamic Model for Ablative Behavior of ZrC-Coated C/C Composites

Abstract

The ablation behavior of ZrC-coated C/C composites is a complex coupling process involving thermal, mechanical, chemical interactions, formation and propagation of cracks. In the present study, we propose a peridynamic (PD) thermo-mechanical-oxidation-diffusion coupled model to describe such a phenomenon comprehensively. Firstly, motion and heat transfer equations are formulated, incorporating growth strain governed by the Clarke model. The oxidation rate of the material is evaluated using diffusion equilibrium and oxidation equations. In addition, the effects of oxidation on different materials are considered, such as growth strain in ZrC materials and material consumption caused by oxidation of C/C composites. To characterize the material failure caused by mechanical and chemical reactions in ablation, a porosity criterion is proposed and its effect on diffusion is considered. The reliability and accuracy of the proposed PD model are validated by analyzing the oxidation process of C/C composites and ZrC and comparing with experimental results. Further, the model effectively captured the crack propagation and oxidation of ZrC-coated C/C composites in an oxyacetylene environment.