基于相关性分析的载荷-强度干涉模型

传统载荷-强度干涉模型适用于零件及系统的静态可靠性分析,并且模型中假设载荷与强度是相互独立的.因为当考虑强度退化时,零件的剩余强度是载荷大小及载荷作用次数的函数,所以传统的载荷-强度干涉模型不能用于分析强度退化时零件和系统的可靠性.通过定义次数等效系数和参考载荷,提出考虑载荷和强度相关的载荷-强度干涉模型,用于分析随机载荷作用下强度退化时零件及系统的可靠性.此外,由于承受共同的随机载荷而产生的共因失效对于系统的可靠性分析具有较大影响,因此建立了考虑共因失效的系统可靠度计算模型.最后通过算例证明提出模型的可用性和合理性.

Load-Strength Interference Model Based on Correlation Analysis

The conventional load-strength interference model is suitable for the static reliability analysis of a component, where the load is independent of strength. With the strength degradation taken into account, the residual strength of a component is the function of the magnitude and frequency of loading. The conventional load-strength interference model is therefore unable to analyze the reliability of a component or system if the strength is in degradation. By defining the equivalent coefficient of the loading frequency and referential load, a load-strength interference model considering the correlation between the load and the strength is developed, which can be used to evaluate the reliability of a component or system in strength degradation under random load. In addition, the common cause failure due to sharing the same random load affects greatly the reliability analysis of a system. A reliability model is developed for the system considering the common cause failure is derived. A numerical example is given to show the rationality and effectivity of the reliability model.