机械零部件的动态可靠性分析

传统的零部件可靠性模型不能很好地反映变幅随机载荷和强度退化对可靠性的影响，忽略了可靠度和失效率随使用时间的变化规律。运用顺序统计理论和随机过程建立了考虑变幅随机载荷和强度退化下机械零件的动态可靠性功能方程模型，利用二阶矩和摄动方法求出可靠性指标并计算出动态可靠度。研究了机械零件强度、载荷、可靠度和失效率随时间的变化规律，给出了可靠度和失效率随使用时间变化的动态过程曲线。实例计算结果表明：建立的功能方程模型符合实际工况，得到的动态过程曲线对零部件试验时间和可靠性寿命的确定具有一定的指导意义。

Dynamic Reliability Analysis of Mechanical Components

The traditional reliability model of components can not well reflect the effect of loads of stochastic-changed amplitude and strength degradation on reliability due to neglecting changes of reliability and failure rate with used time.Considering stochastic loads of variable amplitude and strength degradation,a functional equation model for dynamic reliability of mechanical components Was established based on random process and order statistics theory,and then reliability index and dynamic reliability of components were obtained according to second order moment method and perturbation method.Variation rules of strength,loads,reliability and failure rate of mechanical components with used time were studied and dynamic curves of reliability and failure rate VS used time were also given.The calculated results by a real example show that the functional equation model established is in accordance with practical working conditions,and the dynamic curves obtained possess certain guiding signifieance for determining test time and reliable life of components.