固体火箭发动机的概率设计

Probability Design for the Solid Rocket Motor

固体火箭发动机的性能参数和结构参数一般都服从正态分布，利用应力—强度干涉理论，通过正态分布密度函数的耦合方程进行发动机结构设计，并推导出具有随机变量指数的发动机工作压强和燃烧室壳体弹塑性爆破压强的均值和标准偏差表达式，导出传统安全系数与可靠概率的关系。该设计方法较之传统的采用安全系数的设计方法合理。

The performance and structural parameters of the solid rocket motor generally obey the normal distribution. According to the stress-strength interference theory, the structural design of the solid rocket motor is done by means of the coupling equation of the normal distribution function. The expression formulae of mean values and standard deviations for the operation pressure of motor and elastic-plastic burst pressure of the chamber case are derived, and the relationship between the traditional safety factors and reliablity probability are also derived.