The in-plane coefficients of thermal expansion (CTEs) are important parameters of woven ceramic matrix composite (CMC) in the processes of design, manufacture and utilization. In this paper, five-harness satin woven C/C composites with different volume fractions of matrix fabricated by precursor infiltration and pyrolysis (PIP) method are used for microstructure observation and in-plane CTEs tests. The morphological features and evolution process of defects are studied via analysis of scanning electron microscope (SEM) figures. The improved semi-analytical method and the improved finite element method (FEM) on prediction of the equivalent in-plane CTE of woven CMC considering the effects of defects are established. The improved methods are validated by the results of experiments. Therein the improved semi-analytical method is more efficient in calculation. The improved FEM needs to establish complicated finite element models, but it can reveal the structural details and the deformation mechanism after heating.

平面内热膨胀系数（CTE）是编织陶瓷基复合材料（CMC）在设计，制造和使用过程中的重要参数。本文采用前驱体浸润和热解法（PIP）制备的具有不同体积分数的基体的五线缎缎C / C复合材料用于微观结构观察和面内CTE测试。通过扫描电子显微镜（SEM）图像分析，研究了缺陷的形态特征和演化过程。建立了考虑缺陷影响的机织CMC等效面内热膨胀系数预测的改进半分析方法和改进有限元方法。实验结果验证了所提方法的有效性。其中，改进的半分析方法计算效率更高。改进的有限元方法需要建立复杂的有限元模型，但是可以揭示加热后的结构细节和变形机理。