模糊可靠性分析的等效正态隶属函数法

Analytical Method of Fuzzy Reliability Based on Equivalent Normal Membership Function

针对模糊可靠性分析难以获得解析解,而用数字仿真法求解过于复杂的问题,提出了将非正态模糊变量变换为等效的正态模糊变量,建立一种统一的模糊可靠性分析方法。给出了几种对称型隶属函数的等效正态隶属函数,并通过算例对等效前后隶属函数曲线以及模糊失效事件的概率进行了比较,表明了此方法具有较好的精度。

It is almost impossible to obtain the analytical formulae of computing fuzzy reliability in the analysis of fuzzy reliability, and it is complex to analyze fuzzy reliability by using simulation methods in some cases. Therefore, in order to establish a simple and unified analytical method of fuzzy reliability, non-normal fuzzy variables were transformed to normal fuzzy ones. Also, equivalent normal membership functions that transformed from some symmetrical non-normal membership functions were derived. At last, examples were given to compare the difference of curves between symmetrical non-normal membership functions and their equivalent normal membership functions, and the differences between the computed probabilities of fuzzy failure event by using two different membership functions above. The results showed that by using the method there is enough accuracy.