Research on Failure Criterion of High Energy Solid Propellant under Complex Stress State

摘要

At present, the failure criterion for failure assessment of solid rocket motor(SRM) grain is mainly based on uniaxial tensile properties at home and abroad , and the safety factor is estimated based on the maximum tensile strength and elongation. During the storage or operation of the SRM, the propellant grain is in a multidirectional stress state, and the maximum elongation of uniaxial tension as the limit of failure restricts the accuracy of the evaluation. The stress states of four typical specimens of high-energy propellant under uniaxial tension, biaxial strip tension, cruciform biaxial tension and uniaxial tension under the confining pressure are analyzed, and the influence factors of stress state on failure performance of propellant are determined. The correlation between the ultimate strain of multiaxial tension-compression and uniaxial tension is established. A failure prediction method which introduces the influence of multiaxial stress state in the Mises failure criterion is proposed, and the rationality of the method is verified by the structural integrity analysis and ground test of an SRM.