Multi-scale mechanical-thermal coupling analysis of multi-layer thermal protection structure of ceramic matrix composites

Abstract The wall of combustion chamber needs to sustain the extremely high thermal and stress load in the engine environment, so the thermal protection structure is required to ensure its safe work. At present, the multi-layer thermal protection structure with ceramic matrix composite (CMC) materials has gradually been applied as the internal resistant layer, due to its high specific strength and high temperature resistance. The mechanical-thermal coupling analysis method for CMC multi-layer thermal protection structures needs to be established, considering the complex distributed thermal and stress loads inside the combustion chambers. Firstly, for the local periodic unit of multilayer thermal protection structure, the mesoscale braided structure model and the homogenized model are constructed respectively, to explore the influence of the braided structure inside CMC layer on the temperature and stress distribution. Then, the macroscale model of the multi-layer CMC thermal protection structure is established, based on the feasibility of the local periodic element model verification method. The mechanical-thermal coupling analysis of the overall multi-layer thermal protection structure is carried out, and the temperature distribution and structural deformation are explored.