Thermomechanical fatigue damage evolution of fiber-reinforced ceramic–matrix composites under multiple loading sequences

摘要

In this article, the thermomechanical fatigue damage evolution of fiber-reinforced ceramic–matrix composites subjected to multiple loading sequences is investigated. The damage evolution models considering synergistic coupling effects of thermomechanical fatigue loading sequences, thermal cyclic temperature, and multiple thermomechanical fatigue damage mechanisms (i.e. matrix multi-cracking, fiber/matrix interface debonding/sliding/wear) are developed. The effects of composite material properties, peak stress, and matrix crack spacing on the thermomechanical fatigue damage evolution of fiber-reinforced ceramic–matrix composites are discussed. Comparisons of damage evolution between the in-phase and the out-of-phase thermomechanical fatigue loading under multiple loading sequences are performed. The thermomechanical fatigue hysteresis energy, hysteresis modulus, peak strain, and interface debonded length of cross-ply ceramic–matrix composites subjected to different loading sequences are predicted. The damage under thermomechanical fatigue multiple loading sequences is much more serious than that under thermomechanical fatigue single peak stress level.