模糊可靠性分析一次二阶矩法

文章给出了连续模糊变量变换为当量连续随机变量时其当量概率密度函数的一般表达式,并推出了具有线性隶属函数和正态型隶属函数2种常用模糊变量时当量概率密度函数的具体表达式,得出了2种常用模糊变量的当量均值和当量标准差,从而首次用传统可靠性理论中的一次二阶矩法分析复杂情况下的模糊可靠性;算例表明采用文中方法既可容易地分析模糊可靠性,又能较直观地用可靠性指数度量模糊可靠性。

Fuzzy reliability analysis based on the FOSM method

The general formula of the equivalent probability density function is given by means of the transformation from continuous fuzzy variables to equivalent continuous random variables.The concrete formulae of the equivalent probability density function are derived when the membership functions of the fuzzy variable are two commonly used ones,i.e.,the linear membership function and the normal membership function.Then the equivalent mean values and the equivalent standard deviations of the above two kinds of fuzzy variable are obtained.For the first time,the First-Order Second-Moment(FOSM) method in the conventional reliability theory is used to analyze fuzzy reliability in complex cases.An example shows that by applying the presented method it is easier to analyze fuzzy reliability and fuzzy reliability can be measured more directly by using the reliability index.