【摘要】 针对工程结构系统的极限状态方程通常为隐式,且计算工作量较大的情况,提出一种基于对分区间抽样法的结构可靠性灵敏度分析方法.所提方法综合结构可靠性分析验算点法和对分区间抽样法思想,先根据Taylor公式将初始点附近的状态方程线性展开,依据梯度信息确定最优步长;之后,采用对分可靠度指标β抽样步长区间的方法来确定新的抽样点;最后,经过若干次迭代找出满足结构系统精度要求的设计验算点(MPP),计算可靠度,并根据抽样路径信息算得各影响参数对应的灵敏度.给出了数值算例和工程算例,通过与以往解决隐式结构的可靠性分析方法比较,结果显示所提方法具有收敛可靠、抽样次数少的优点,尤其适用于分析大型复杂隐式结构系统可靠度问题.更多还原

【Abstract】 Targeting the problem of limit state equations being often implicit and demanding agreat amount of computation,an analysis method was proposed for structural reliability sensitivity based on the bisection method of sampling.Combining with the most probable point method of structure reliability analysis and the bisection method of sampling,the proposed method first linearizes the state equations near the initial point based on Taylor expansion method and determines the optimal step-length based on gradient information;then,it locates the new sampling point by means of bisect sampling step-length of reliability indexβ;finally,by several iterations,it finds out the most probable point(MPP)that meet the accuracy requirement of the structures and system to calculate reliability and reliability sensitivity of influencingparameters according to the information of the sampled path.Examples of the computation and engineering were given.A comparison with existing methods for solving implicit structure reliability problems indicated that the proposed method possesses the advantages of reliable convergence and less sampling,making it especially suitable for performing reliability analyses of large-scale complicated implicit structures and systems.更多还原