Storage life prediction for solid rocket motor grain in consideration of Poisson's ratio

A cube that contains a single small pore was taken as a representative volume element(RVE), Combined with elasticity formula, the relationship between solid propellant void content and the instantaneous Poisson's ratio was deduced, and the change law of Poisson's ratio with solid propellant aging was obtained. The change laws of instantaneous modulus' evolution and maximum elongation rate of propellant with storage time were obtained through the propellant accelerated aging test. With instantaneous modulus and instantaneous Poisson's ratio as aging parameters, three-dimensional viscoelastic finite element method was used to calculate the maximum Von-Mises strain of a SRM grain with different storage time. By comparing the computing results with the propellant mechanical properties of different storage time, the storage life of the SRM grain was predicted.