基于失效行为的机械零部件寿命概率分布特征计算方法

Method for Calculating the Life Probability Distribution Characteristic of Mechanical Components Based on the Failure Behavior

针对机械零部件的寿命预测及其概率分布特征确定问题,从影响零部件寿命及其概率分布特征的基本因素出发,采用应力-强度干涉方法描述零部件的失效行为,研究基于失效行为的零部件寿命概率分布特征确定方法,建立以时间为寿命度量指标时零部件的寿命概率分布模型,给出能够体现'应力、强度及其退化'等参数影响的零部件寿命累积分布函数和概率密度函数以及平均寿命计算模型,研究零部件寿命概率分布特征的变化规律。运用所建立的方法及模型,能够在设计阶段根据零部件的结构设计参数以及使用剖面科学地确定零部件的寿命概率分布特征,可以更好地指导零部件的设计、试验、使用、维修等。

As for the problem of life prediction of mechanical components,the essential factors affecting the life and its probabilistic characteristics is taken in account and the failure behavior of components is described with the stress-strength interference method.Then,the method for determining the probability distribution of life of components with time as life parameter is studied,and the cumulative distribution function,the probability density function and mean life function of components,which can embody the effect of parameters including stress,strength and its degradation,are developed.The rules that the life probabilistic characteristics of components change as the parameters of stress and strength,are studied.With the method and model proposed,according to the structural parameters and operating profile of components,the life probability distribution characteristic can be determined in the development stage,and the process of design,test,operation and maintenance of components can be directed more scientifically.