【作者】 朱卫兵；

【导师】 安伟光；

【作者基本信息】 哈尔滨工程大学 ， 固体力学， 2005， 博士

【摘要】 长期以来，固体火箭发动机的可靠性问题一直受到人们的高度重视，特别是可靠性设计已经成为固体火箭发动机研制过程中必不可少的环节。固体火箭发动机属于一次性使用的不可修复的复杂系统，由于承受高温、高压、高热流、高速气流和飞行过载等随机因素的影响，因此在地面试验和飞行过程中，如不能按预定程序工作或因自身结构存在固有缺陷，极易出现故障，甚至发生意外事故。因此从理论上和工程实践中开展固体火箭发动机的结构完整性分析和可靠性研究是十分必要的。 固体火箭发动机装药是发动机重要组成部分，其结构完整性和可靠性将直接影响发动机整体可靠性。 本论文以某型固体火箭发动机为背景，完成了药柱结构完整性及可靠性研究。首先根据线性粘弹本构关系，研究了装药的粘弹泊松比、装药体积松弛模量及装药应力松弛模量的粘弹行为和相互转换关系。通过已知数据，应用Prony级数展开，得出了装药应力松弛模量主曲线；推导并给出了轴向固有周期下线性加载动力放大系数随线性加载时间的变化关系。 文中分析了轴向高过载下药柱的结构完整性，利用大型计算软件ANSYS成功地模拟了药柱的粘弹动力响应。针对某固体发动机的故障树分析结果，根据主要影响因素进行了自由装填式药柱的轴向受载分析、高温下贴壁状态药柱的轴向受载分析和公路运输振动环境下的随机疲劳分析。结合相应的药柱破坏判据，轴向过载分析表明，药柱结构完整性能够保证，但安全系数过低。 本文采用瞬时可靠度进行了药柱在轴向高过载下的可靠性分析。考虑加速度载荷的随机性，以及推进剂松弛模量、泊松比、抗拉强度和轴向位移允许值等参数的分散性，基于ANSYS概率设计系统进行了实际发动机药柱在轴向过载下的瞬时可靠度分析，分析中利用Monte Carlo法作为可靠度计算手段，同时计算了强度和刚度两种失效模式下瞬时可靠度，并进行了失效灵敏度分析。分析表明，两种失效模式下的瞬时可靠度均随第二次加载时间的增加先逐渐减小，在某时刻达到最小，之后又逐渐增加。灵敏度分析表明，泊松比对两种失效模式下瞬时可靠度的影响很小；在强度失效模式中，推进更多还原

【Abstract】 Since long term, the reliability problem of a solid rocket motor has been highly considered, and especially probability design has already become an absolutely necessary tache during designing and manufacturing solid rocket motors. A solid rocket motor is a complicated system which can be used only once and can not be repaired. Because of the effect of the random factors such as high temperature, high pressure, high heat flow and so on, the motor is prone to fail and even results in contretemps when it can not work as preset sequence or has inherent defect in its structure. So it is very necessary to do research in the structural integrity and the structural reliability of solid rocket motors on the basis of theoretics and engineering practice.As a significant ingredient of a solid rocket motor, the structural integrity and the structural reliability of the solid rocket motor grain can directly influence the reliability of the whole solid rocket motor.According to one solid rocket motor ,this paper has accomplished the study on the structural integrity and the structural reliability of the solid rocket motor grain. Firstly, based upon linear viscoelastic constitutive equation, the viscoelastic behaviour of viscoelastic Poisson ratio, bulk relaxation modulus and stress relaxation modulus of the grain and the interconversion of these parameters are studied. By given material data, using Prony Series, the primary curve of the stress relaxation modulus of the grain is obtained. According to axially natural period, the relation of the dynamic magnification factor vs the linearly loading time under linearly loading is deduced and presented.The essay has analyzed the structural integrity of the grain under axially high overload ,and the viscoelastic dynamic response of the grain is successfully simulated using large-scale computation software ANSYS. Adopting the results of Failure Tree Analysis of the motor and according to the primary influencing factors, the article has analyzed the free-filling grain under axially loading , has studied the grain with outer surface fixed to the case under axially loading at high更多还原