定应变下固体火箭发动机药柱概率贮存寿命预估研究

To investigate the effects of constant strain on the probabilistic storage life of solid rocket motor (SRM) grain, the digital characteristic of mechanical property parameters of solid propellant with storage time was derived from the statistical analysis of high-temperature accelerated aging test data. The mean and standard deviation of Von Mises strain of grain in the combined action of internal pressure and overload were calculated using stochastic finite element method (SFEM). The structure reliability of grain and its variation tendency under different strain sensitivity coefficient with storage time was calculated by using stress-strength interference model. On the basis of calculation results, the probabilistic storage life of the SRM grain under different constant strain was predicted with a lower limit of reliability coefficient of 0.97. Results show that the constant strain has an obvious effect on the probabilistic storage life of SRM grain. The probabilistic storage life was about 30.98 years when sensitivity coefficient was 2.94, and 0.92 years when sensitivity coefficient was -2.94. The probabilistic storage life of the grain increases as strain sensitivity coefficient increases in this interval.