通过对热化学烧蚀机制的分析,利用有限元方法分析了热化学烧蚀、烧蚀表面退缩及温度场耦合作用下C/C复合材料的烧蚀性能变化规律。采用虚拟失效、重新构建网格部件的方法实现烧蚀表面的退缩,建立了烧蚀表面退缩下瞬态温度场的有限元模型。运用热化学烧蚀理论求解了进入材料内部的净热流和烧蚀率。烧蚀表面退缩后变得不规则,通过编程校正了重新加载热流时不规则表面出现局部热流偏大的现象。结果表明,随着烧蚀时间的增加,进入材料内部的热流达到动态的平衡,材料的烧蚀是多种因素综合作用的结果,通过耦合计算可以真实反映材料的烧蚀特性。
In this paper,according to the analysis of the thermo-chemical mechanism,the change rules of ablation properties of the C/C composites in thermo-chemical ablation,ablation surface receding and temperature field coupling were investigated by finite element method.The receding of the ablation boundary by virtual failure and rebuilding orphan mesh part was achieved,and finite element model of ablation temperature field at receding boundary conditions was established.The net heat flux flowed into the material and ablation rate were calculated by the thermo-chemical ablation theory.The phenomenon of large local heat flux on the irregular surface was corrected by programming after ablation surface receding when the heat flux was reloaded.The result shows that as the ablation time increases,the heat flux flows into composite materials will reach a dynamic balance.The ablation of the material is the results of a variety of factors and coupled calculation can truly reflect the characteristics of the ablation of the material.