随机不确定分布参数下随机可靠度的超限概率模型研究  

PROBABILITY MODEL OF RANDOM RELIABILITY EXCEEDING REFERENCE VALUE UNDER UNCERTAIN RANDOM DISTRIBUTION PARAMETERS

作　　者：吕媛波[1] 吕震宙[1] 唐樟春[1] 

机构地区：[1]西北工业大学航空学院,西安710072

出　　处：《机械强度》2011年第6期833-838,共6页Journal of Mechanical Strength

基　　金：国家自然科学基金(10572117;50875213);新世纪优秀人才支持计划(NCET-05-0868);航空基金(2007ZA53012);国家863计划课题(2007AA04Z401)资助~~

摘　　要：针对分布参数具有随机不确定性时可靠度也有随机性的问题,建立给定约束可靠度情况下新的失效概率度量指标,该指标可以反映随机可靠度小于约束可靠度的可能性,从而可以更客观地反映随机不确定性分布参数下结构失效的可能性。基于三点估计建立新度量指标的求解方法,给出方法的原理及实现步骤。与通用数字模拟方法相比,所建立的新指标求解的三点矩估计方法在计算精度可接受的条件下效率更高,与一般的解析方法相比,该方法不需要迭代和求导,便于复杂问题的求解。算例在解释新建指标合理性的同时,验证指标求解方法的精度和效率。In case that uncertain distribution parameters are random,the traditional reliability is random as well.For the problem with uncertainty distribution parameters,a new reliability index is established on the probability that reflects the random reliability is smaller than the reference one.The new model can reflect the failure probability of the structure objectively under the uncertain distribution parameters.The detailed implementation of the solutions of the new reliability index are presented on the available three-point estimation.Comparing with the universal numerical simulation,the three-point estimation based methods for the new reliability index possess higher efficiency under the acceptable precision comparing with the analytical method.The three-point estimation based methods require neither iteration nor gradient so that they can be applied in the complex problems.Some samples are given to explain the rationality of the model and validate their precision and efficiency.

关 键 词：约束可靠度 矩方法 三点估计 失效概率 

分 类 号：TB114.3[理学—概率论与数理统计]