双不确定相依竞争失效模型的可靠性评估

Reliability evaluation of dependent competitive failure models with biuncertainty

复杂设备常会经历自然磨损和外力影响,外力致使磨损量突然增大.在工程实践中,很多高可靠性、长寿命的设备,由于不易获得足量的失效数据,须使用专家的经验数据来评估设备的寿命分布和可靠性指标.然而,专家的经验数据往往不是精确的常数,而是一个限定范围.为了处理这种人为认知引起的不确定性,引入不确定理论,用不确定变量刻画专家的经验数据,同时分布函数中的参数也具有不确定性,并用不确定变量描述.在参数为不确定变量情形下,利用不确定理论的方法计算.设备经历了相依竞争失效过程的确信可靠度,系统的确信可靠度高于参数为常数的情形,并用微电子机械系统为例验证了模型的有效性.

Complex equipments often experience natural wear and external forces,and external forces cause a sudden increase in wear.In engineering practice,many high-reliability and long-lifetime equipments can not obtain a sufficient amount of failure data easily,it is necessary to use expert experience data to evaluate equipment’s lifetime distribution and reliability indicators.However,the empirical data of experts is often not an exact constant,but a limited range.In order to deal with the uncertainty caused by human cognition,the uncertainty theory is introduced,and the empirical data of experts is described by uncertain variables.At the same time,the parameters in the distribution function are also uncertain and described by uncertain variables.The uncertainty theory is used to calculate the belief reliability of the equipment undergoing dependent competition failure process.When the parameters are uncertain variables,the belief reliability of the system is higher than that when the parameters are constant,The microelectronic mechanical system is used as an example to verify the effectiveness of the proposed model.