Life probability distribution model of mechanical components with the number of load application as life parameter

With the number of load application as the life parameter, the method for modeling the life probability distribution of mechanical components is studied. First, the failure behavior of mechanical components is analyzed, and the method for describing the failure behavior of mechanical components is developed with the stress–strength interference theory. Then, based on the failure behavior, the life probability density function, life cumulative distribution function, reliability, failure rate, and mean life of component with the number of load application as the life parameter, which can embody the effect of parameters including stress, strength and its degradation, and so on, are derived, respectively. Finally, for the cases of different parameters of stress and strength, the life probabilistic distribution characteristic, reliability, failure rate, mean life, and reliable life of components are studied. The result shows that the life probabilistic distribution characteristic of components is dependent on the specific value of parameters describing the failure behavior. With the method and model proposed in this article, as long as the parameters of strength, stress, strength degradation, and so on are known, the life probabilistic distribution functions of components can be calculated, the rules that the reliability and failure rate of component change as the number of load application can be obtained, and the mean life and reliable life of components can be determined.