基于时变区间和穿阈模型的机械时变可靠性分析方法  

Time Variant Reliability Approach with Time-variant Interval and Upcrossing Model

作　　者：王丕东[1,2] 张建国[1,2] 阚琳洁[1,2] 杨乐昌 

机构地区：[1]北京航空航天大学可靠性与系统工程学院,北京100191 [2]北京航空航天大学可靠性与环境工程技术重点实验室,北京100191

出　　处：《机械工程学报》2017年第11期1-9,共9页Journal of Mechanical Engineering

基　　金：国家重点基础研究发展计划资助项目(973计划;2013CB733000)

摘　　要：现有机械时变可靠性模型主要以概率论为基础,依赖于基本随机变量的大样本空间,当没有足够的数据来验证这些随机变量的概率密度正确性时,分析结果的准确性和置信度值得怀疑,概率可靠性方法存在局限性。在航天机构中,由于成本高,在复杂服役环境中可观测性差、检测难,积累信息难、统计类信息往往难以获得,主要存在区间类信息,为保证分析结果更加精确,考虑时变区间变量,研究并提出非概率时变可靠性分析方法:将时变区间转化为服从截断正态分布的随机过程,求出在时变区间内的上穿率,针对正态截断分布变量,利用改进的非概率PHI方法,求得累积失效概率。解决区间变量随时间变化下的非概率时变可靠性问题。利用算例和工程实例验证本方法的准确性和可行性。Several approaches have been proposed object to solve time variant reliability problems in recent decades based on classical probability theory dealing with problems in practice. Indeed the statistical information of complex mechanical systems, such as aircraft or spacecraft, is always hard to be collected. Interval data are encountered frequently in practical engineering problems. An improved non-probabilistic PHI method is proposed in order to guarantee the accuracy of results with time-variant interval-defined. A time variant interval is converted to a stochastic process distributed the truncated normal as well as the up crossing rate is calculated. Considering the variables with the truncated normal distribution, the cumulative failure probability can be estimated using the improved non-probabilistic PHI method. For demonstration and validation purpose, the method is applied in a case representing a mechanical system （a beam） placed in an environment that can have exceptional configuration.

关 键 词：时变区间 穿阈模型 改进的非概率PHI方法 截断正态分布 

分 类 号：V215[航空宇航科学与技术—航空宇航推进理论与工程]