基于冲击衰减的竞争失效可靠性分析模型

Reliability analysis model of competition failure based on shock attenuation

针对经受竞争失效的机械产品其突发失效过程中冲击存在衰减的现象,根据冲击信号的衰减特性,提出了基于衰减冲击模型的竞争失效可靠性分析计算方法.该方法首先考察具有周期性和随机性特点的两类衰减冲击过程,利用指数函数描述其衰减规律,探讨冲击作用时所产生的冲量.在此基础上构建冲击所造成的损伤与冲量之间的量化模型,通过Wiener过程对连续退化进行描述,进一步推导产品在失效相关模式下的竞争失效可靠性分析模型.最后通过算例比较研究了考虑冲击衰减与否对可靠性评估的差异,为产品可靠性设计提供参考.

Aimed at the existence of shock attenuation phenomenon with the machinery product in its sudfor reliability analysis of competition failure is presented based on shock attenuation model. In this meth od, two kinds of shock attenuation processes with periodic and stochastic characteristics are investigated first, then the exponential function is used to describe the attenuation law, the impulse generated by the shock is explored the quantitative model of relation between the impulse and damage caused by the shock is constructed, the continuous degradation is described by means of Wiener process, and further a reliability analysis model of competition failure of the product is derived based on the dependent failure mode. Final ly, the difference of the reliability assessment with and without consideration of shock attenuation is corn paratively studied by means of a computation example, which will provide a reference for the reliability de sign of the product.