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针对失效域具有模糊性的渐变结构系统,提出了模糊可靠性灵敏度分析的矩方法。所提方法首先依据功能函数的取值,将模糊失效概率的积分区域离散为一系列的子区域,使得隶属函数在离散化的子区域内近似保持为常数,从而将模糊失效概率的计算转化为一系列清晰子区域中的随机失效概率与该区域隶属函数近似值乘积的计算,并将模糊可靠性灵敏度分析问题转化为一系列子区域的随机可靠性灵敏度分析,而子区域中的随机可靠性灵敏度可由所建立的矩方法来求得。所提方法的主要优点是对中、低维隐式功能函数具有较高的效率,同时它对多模式和非正态基本变量情况也具有很强的适应性。虽然所提方法的计算工作量随变量维数的增加而呈指数增加,但在变量维数小于 10 时,其效率在现有方法中是相当有竞争力的。大量的算例被用来证明所提方法的优点。
Aiming at the gradual change of the fuzzy system with failure field, a moment method of fuzzy reliability sensitivity analysis is proposed. The proposed method firstly discrete the integral region of fuzzy failure probability into a series of sub-regions based on the value of the function, so that the membership function remains approximately constant in the discretized sub-region, so that the calculation of the fuzzy failure probability is converted into The calculation of the product of the probability of stochastic failure in a series of clear subareas and the approximation of the membership function of the region transforms the problem of fuzzy reliability sensitivity analysis into a series of random reliability sensitivity analysis of sub-regions. The stochastic reliability sensitivity The moment method can be established. The main advantage of the proposed method is that it has high efficiency for implicit functional functions of medium and low dimensions, and it also has strong adaptability to multi-mode and non-normal basic variables. Although the computational effort of the proposed method increases exponentially with the increase of the number of variables, its efficiency is quite competitive in the existing methods when the number of variables is less than 10. A large number of examples are used to prove the advantages of the proposed method.