考虑环境因素及可信度的可靠性仿真方法

Reliability Simulation Considering Environmental Factors and Credibility

为了处理现实中随机性、模糊性和不完全可信性并存的情形,基于云理论和故障树分析技术研究了考虑环境因素和可信度的可靠性仿真方法。首先运用正态云模型将定性的、模糊的环境因素转变为对可靠性的定量影响,然后运用正态云、指数云模型描述失效概率密度函数的不完全可信性,再结合故障树分析技术提出算法框图并应用于某机电作动器的可靠性仿真,得到平均故障间隔时间的分布、部件的重要度和可靠度区间。经对比分析,验证了该算法可有效描述多种不确定并存的情形,同时明确了可靠性对温度因素敏感的若干部件。

The coexistence of randomness,fuzziness and incomplete credibility is common in reality. A reliability simulation algorithm considering environmental factors and credibility was studied based on the cloud theory and the fault tree analysis. Firstly,fuzzy qualitative descriptions of environmental factors were turned into quantitative influences on reliability index based on the normal cloud model. Then,the normal cloud model and exponential cloud model were applied to deal with incomplete credibility problem of failure probability density functions＇ parameters. After that,flow diagram of the algorithm was proposed and applied to reliability analysis of a certain electromechanical actuator,then the normal distribution function of mean time between failure,components＇ importances and intervals of reliability were acquired. By comparing with the results of the traditional method,it is proved that the algorithm can be applied to the situation with several uncertainties coexisting. Simultaneously,the components whose reliability were sensitive to temperature factor were demonstrated in the end.