Abstract: In order to study thermo-structural characteristics of the four-directional carbon/carbon(C/C) composites on mesoscopic of throat in solid rocket motor, based on the component of interface, the experimental thermophysical properties and prediction of the effective thermophysical properties on the representative volume element were completed. The effective thermal expansion coefficient and the effective thermal conductivity of the 4D C/C composites are obtained. The analysis results show that a procedure for the periodic boundary condition of temperature is realized based on the representative volume element, which can accurately predict the effective thermal expansion coefficient and the effective thermal conductivity of the 4D C/C composites. The influence of the component of interface on the effective thermophysical properties is obtained. The interface is established with a certain thickness more in line with the experimental measurement results. The influence of braiding parameters on the effective thermal expansion coefficient and the effective thermal conductivity are discussed.

Key words: Four-directional carbon/carbon composites;Thermo-structural characteristics;Interface;Periodic boundary condition of temperature;Representative volume element;Thermal expansion coefficient;Thermal conductivity

摘要： 为研究固体火箭发动机喉衬用轴编C/C复合材料的细观热结构特性，以组分材料之间界面分析为基础，完成热结构参数的实验测定与基于代表性体积单元的等效热物理参数的预测，得出轴编C/C复合材料的等效热膨胀系数与等效热导率系数。分析表明：基于代表性体积单元程序温度周期性边界条件的应用，可以较精确预测复合材料等效热膨胀系数和等效热传导率；得出了组分材料界面相对等效热结构参数的影响，组分材料界面相采用一定厚度的单元模拟更加接近实验数据；讨论了等效热膨胀系数和等效热导率随编织参数的变化规律。

关键词: 轴编C/C复合材料;热结构特性;界面;温度周期性边界条件;代表性体积单元;热膨胀系数;热导率