CMC strength and damage prediction considering thermal mechanic coupling effect

Abstract

Continuous Fiber Reinforced Ceramic Matrix Composites (CMC) confront significant and undeniable elevated thermal gradient. In this study, a periodic RVE geometrical model was simplified based on the XCT scanning images of 2.5D woven CMC, and the model of the thermal structural strength of 2.5D woven CMC under the influence of fine-scale temperature fields was developed. In conjunction with the temperature distribution of the aero-engine turbine working state, ten sets of temperature field conditions were established and the model of thermal structural strength of 2.5D woven CMC under the influence of fine-scale temperature fields was developed. The effects of the overall temperature level, the form of the temperature difference and the size of the temperature difference on the tensile curve, the failure limits, the form of damage evolution, and the distribution of the failure unit at the time of failure of the 2.5D woven CMC were discussed. It was found that the temperature field induced by temperature difference in the thickness direction has a more significant effect on the tensile mechanical properties of the material, which is a key consideration for the structural design process using this material.