不确定理论下竞争失效系统的可靠性分析

针对有新研发产品，故障数据较少的复杂系统，提出了不确定环境下自然退化和外部冲击相互独立的竞争失效模型。考虑了系统同时遭受自然退化和外部冲击，连续的自然退化用一个不确定过程刻画，冲击到达的时间间隔和每次冲击对系统造成的损坏量分别用2个不同的不确定变量来刻画。运用不确定理论，分别在极端冲击模型、累积冲击模型、δ冲击模型下，研究了系统的确信可靠度，结果表明:在有新研发的产品、故障数据较少的复杂系统，用不确定理论的方法来描述模型更合适，并通过数值分析显示了模型的有效性。 

Reliability analysis for systems subject to competing failure processes based on uncertainty theory

For complex systems with newly developed products and less failure data, a competitive failure model in which natural degradation and external shocks are independent of each other in an uncertain environment is proposed. Considering that the system suffers from natural degradation and external shocks at the same time, the continuous natural degradation is described by an uncertain process, and the time interval of the shock arrival and the damage to the system caused by each shock are described by two different uncertain variables. Using the uncertainty theory, the system belief reliability is studied under the extreme shock model, cumulative shock model, and δ shock model. The results show that in the case of newly developed products and complex systems with less failure data, the method of uncertainty theory is more appropriate to describe the model, and numerical analysis shows the effectiveness of the model.