A model, based on the oxidation kinetics model of unidirectional C/SiC composite (between 400 °C and 800 °C in air, P = 100 KPa), is developed to predict the coefficient of thermal expansion (CTE) of 2.5D C/SiC composites. It takes into account (i) the changes versus time and temperature of the geometry of the notch resulting from the consumption by oxidation of the carbon interphase and fiber, (ii) the accumulation of oxidation damage of the carbon interphase and fiber in C/SiC microcomposite (one single filament) versus temperature during heating, (iii) the multiscale analysis of CTE of 2.5D C/SiC composites. The CTE of 2.5D C/SiC composites in warp direction during heating in air oxidizing environment are evaluated and validated in comparison to experimental data. The results indicate that the predicted CTE of 2.5D C/SiC composites in warp direction agree well with the experimental data.

基于单向C / SiC复合材料的氧化动力学模型（空气中400°C至800°C之间，P = 100 KPa），可预测2.5DC / SiC复合材料的热膨胀系数（CTE）。它考虑了（i）碳的界面和纤维的氧化消耗所导致的缺口的几何形状随时间和温度的变化;（ii）C / SiC中碳的界面和纤维的氧化损伤的积累微复合材料（一根单丝）与加热过程中的温度之间的关系；（iii）2.5DC / SiC复合材料CTE的多尺度分析。与实验数据相比，评估并验证了2.5DC / SiC复合材料在空气氧化环境中加热时在翘曲方向上的CTE。结果表明，2.5DC / SiC复合材料在翘曲方向的预测热膨胀系数与实验数据吻合良好。