Abstract: The temperature and stress fields of solid rocket motor (SRM) throat made of needled integral felt C/C composites during and after firing process are calculated using finite element method (FEM) in this paper. The calculated maximum stress in nozzle throat is compared with the final strength obtained in the material test. It has been found that the nozzle throat with needled integral felt C/C composites is safe during SRM firing, but the final axial tensile stress of nozzle throat after SRM firing exceeds the material tensile strength, leading to structure failure. The results are verified by SRM firing test and scanning electron microscope (SEM) analysis.

Key words: failure, ultimate strength, needled integral felt C/C composite