Effects of tensile fatigue loads on flexural behavior of 3D braided C/C composites

3D braided C/C composites have been prepared by an isothermal chemical vapor infiltration (CVI) process, and the evolution of flexural behavior perpendicular to the fiber direction after tensile fatigue loads was examined. The results show that the flexural property of C/C composites was enhanced with the increase in fatigue cycles, and the fracture mode also evolved from "brittle" of original samples to "pseudo-plastic" of fatigued samples. It is suggested that the weakened interface and reduced residual thermal stresses by fatigue loads play important roles in enhancing the property of C/C composites.