一种考虑失效准则模糊性的时变可靠度分析方法
A Time Varying Reliability Analysis Method Considering Fuzzy Failure Criterion

针对工程结构失效准则不确定性的时变可靠度问题,构造了一种考虑失效准则模糊性的时变可靠度分析方法,可处理模糊失效准则下抗力和荷载随时间变化的可靠性计算问题。该方法首先将模糊失效准则下的时变功能函数随机过程进行离散,然后应用模糊集基本理论,引入新的随机变量,得到不同时间段的等效功能函数,最终将模糊失效准则下的时变可靠性问题转化为常规的可靠性问题,通过一次二阶矩方法求解获得时变可靠度和失效概率。最后以某机械零件和齿轮传动为例,分别得出模糊失效准则下的时变可靠度曲线和失效概率曲线,验证了该方法的有效性。
The time varying reliability analysis method considering fuzzy failure criterion is proposed to deal with the time varying reliability problems of the engineering structures, which can be used to solve the reliability problems with time varying loads and resistances. In this method, the time varying random processes performance function subject to fuzzy failure criteria is firstly discretized, then the basic theory of fuzzy sets is applied and new random variables are introduced to get the equivalent performance function in different time periods. Eventually the time varying reliability problem subject to fuzzy failure criterion is simplified into a static probabilistic reliability problem, which can be solved by a second moment method and the time varying reliability and failure probability can be obtained. Finally, a type of machinery parts and gears are investigated as examples, and the time varying reliability curve and failure probability curve subject to fuzzy failure criterion is obtained. The results show the effectiveness of the present method