Structural assessment of a solid propellant rocket motor: Effects of aging and damage

The aim of this study is to perform structural analysis of a solid propellant rocket motor using the finite element method and to determine the effects of aging on the analysis results. Thermal and pressure loadings occurring during the shipping, storing and firing are considered to be the most critical in determining long-term behavior of the motor. Stress and strain distribution in the rocket motor under these loading conditions are determined. Maximum hoop strain at the surface of the propellant and bond stresses at the interface between the liner and the insulator are evaluated as indicators of cracking in the propellant grain and debonding at the liner–insulator interface. The analyses are performed for both unaged and aged propellants. The results can be used to estimate the service life of the motor.