Study on the ablation behavior of C/SiC composite materials under the action of local structural thermal sources.

• Local structural heat sources with different heat flux densities are used to simulate local extreme environments at discontinuities in spacecrafts. • The thermal response, ablation law, and multi-scale ablation morphology of typical thermal protection materials (C/SiC) under the action of local heat sources are analyzed. • Improve the ablation retreat program (Umeshmotion+ALE) in the ABAQUS software so that C/SiC composite materials with large ablation amount until material perforation can be simulated numerically. This study uses ablation testing on C/SiC composite materials under local structured thermal sources with a wide range of heat flux densities, simulating the harsh local conditions caused by discontinuous structural interference on spacecrafts. The thermal response, ablation laws, and ablative perforation time of C/SiC composite materials are obtained under different heat flux densities. The experimental findings demonstrate that there are notable differences in the morphology of the ablation pits under various heat flux conditions. As the heat flux density increases, the temperature of the local structure heat source action center on the target surface increases, the depth and outer diameter of the erosion pits increase, and the wall surface of the erosion pits gradually tends to be smooth. Under the influence of local structural heat sources, the creation of material ablation pits and the process of material perforation are predicted using the improved Umeshmotion+ALE+birth and death element method. For various conditions, the temperature field results and ablation morphology are well predicted by the numerical simulation results. Numerical calculations can be used to analyze the thermal stress and oxidation sublimation contribution rates of targets under the action of structural heat sources. [ABSTRACT FROM AUTHOR]