关键词: 指数函数, 区间型退化, 失效分布, 数值积分, 可靠性

Abstract: In a classical degradation experiment, the performance of a product is reduced or raised to a certain threshold value, which is regarded as a product failure; this is often refereed to as single-point degradation. Although this definition is widely used, it is not sufficiently comprehensive and cannot be used alone to describe the full product degradation process. In this study, we improve the single-point degradation model and propose the interval degradation model; in this context, the previously fixed threshold value will be generalized to a random value at a specified interval. We discuss the lifetime distributions for a variety of interval degradation models when the degradation path is an exponential function. Numerical integration and Monte Carlo simulation are used to calculate the lifetime distribution for interval degradation models and single-point degradation models; in addition, we determine the relationship between the respective models. The simulation results reveal that the performance of the interval degradation model is more reasonable and effective than that of single-point degradation model.

Key words: exponential function, interval degradation model, failure distribution, numerical integration, reliability