【摘要】 为了研究不确定性陶瓷热防护系统(thermal protection system,简称TPS)的动态响应概率分布,提出了外部随机激励作用下的不确定性TPS双随机动态理论模型,其将防热瓦简化为质量点,将应变隔离垫(strain isolation pad,简称SIP)简化为线性弹簧和阻尼单元,且以上质量点、弹簧刚度和阻尼均服从正态分布。采用摄动法研究了防热瓦加速度以及SIP动态应力的概率分布,其关键是进行响应均值对TPS随机参数的灵敏度分析。利用本研究理论方法和Monte Carlo数值方法进行了响应概率分布的计算,结果表明,理论方法与Monte Carlo数值方法计算获得的响应均值及标准差吻合得很好,验证了该动态理论模型的正确性和分析精度,为防热瓦不确定性加速度响应、SIP不确定性动强度和TPS不确定性动态完整性分析提供了理论基础。更多还原

【Abstract】 In order to study the probability distributions on the dynamic responses of the uncertainty ceramic thermal protection system(TPS),a double random dynamic theoretical model for uncertainty TPS under the outer random excitations is presented in this paper.In the theoretical model,the tile is simplified as a mass point,the strain isolation pad(SIP)is simplified as a linear spring and a damping unit,and the above mass point,the stiffness of spring and the damping all obey the normal distribution.The probability distributions for acceleration of the tile and the dynamic stress of SIP are studied by aperturbation method,and the key problem is to obtain the sensitivity analysis of the mean responses to the random parameters of TPS.The theoretical method and Monte Carlo numerical method are used to calculate the probability distributions of responses.The results show that the mean values and standard deviations of the responses calculated by theoretical method match very well with that calculated by Monte Carlo numerical method,which verifies the correctness and analysis accuracy of the dynamic theoretical model presented in this paper.Finally,the works in this paper provide a theoretical basis for the analysis of the uncertainty acceleration of tile,the uncertainty dynamic strength of SIP and the uncertainty dynamic integrity of TPS.更多还原