Improved semi-analytical and numerical methods on prediction of in-plane coefficients of thermal expansion of woven ceramic matrix composite considering defects

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.