The problems of dynamic reliability of a supercavitating vehicle with stochastic parameters under the random excitation were investigated. A supercavitating vehicle was modeled by using eight-node super-parametric shell elements, the impact loads and planing forces of the tail on supercavity vehicle structures were simplified into two stationary random processes that exist a certain phase difference, and the random excitations were accurately transformed into sinusoidal ones in terms of the pseudo excitation method. The random structural stress response was obtained by combining Newmark method with pseudo excitation perturbation method, and then all required digital features for dynamic reliability of the supercavitating vehicle were calculated. The expressions of the mean value and the variance of dynamic reliability of the supercavitating vehicle with stochastic parameters were educed from the first excursion probability mechanism of calculating dynamic reliability, the structure dynamic reliability problems of the supercavitating vehicle with random parameters were solved. Finally, the method of this paper was proved feasible and effective compared with the Monte Carlo method by an example.%针对具有随机参数的超空泡结构在随机激励下的动力可靠性问题,使用八节点超参数壳单元对超空泡航行体建模,将超空泡尾部受到的冲击载荷及滑行力简化成2个存在某一相位差的平稳随机过程,利用虚拟激励法将双随机问题精确地转化为单随机问题.应用Newmark法结合虚拟激励摄动法计算出随机结构的应力响应,进而求出随机参数超空泡结构动力可靠性所需的全部数字特征.由首次超越破坏准则的动力可靠度公式,求出随机参数超空泡结构动力可靠度的均值和方差的计算公式,解决了具有随机参数超空泡结构的动力可靠性问题.通过算例与Monte Carlo方法结果的比较,验证文中方法的可行性和有效性.
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