AN APPLICATION OF EQUIVALENT NORMAL DISTRIBUTION METHOD IN THE RELIABILITY ANALYSIS OF MECHANICAL PRODUCTS WITH MUTIPLE FUZZY VARIABLES

摘要

So far, when there are multiple fuzzy variables in real mechanical design, fuzzy reliability of mechanical products could not be calculated by not only developing fuzzy reliability theory, but also much more mature conventional reliability theory. In the paper, the equivalent probability density functions, the equivalent probability distribution function, the equivalent mean values and the equivalent standard deviations of fuzzy variables are given after they are transformed to equivalent random variables. Therefore, when there are multiple fuzzy variables in limit state equation, it is possible to compute the fuzzy reliability of mechanical products by using equivalent normal distribution method of conventional reliability theory. The paper shows that only using conventional reliability theory can solve the problem of fuzzy reliability. The method in the paper is of theoretical significance and practical value. An example is given to show its reasonableness and feasibility.