Reliability modeling of mixtures of one-shot units under thermal cyclic stresses

Modeling components’ thermal fatigue life due to cyclic temperature fluctuation based on Coffin–Mason principle has been extensively investigated. However, sparse research assesses the thermal fatigue life by providing the reliability metrics of components/systems under thermal fatigue. The Birnbaum–Saunders (BS) distribution is developed to model the unit's fatigue failure induced by mechanical stresses and provides the unit's reliability metrics. In this paper, we investigate a generalized Birnbaum–Saunders (GBS) distribution and its performance in predicting fatigue failure caused by thermal cyclic stresses. We then apply the GBS distribution to model the reliability metrics of a system with mixtures of nonhomogeneous one-shot units subject to thermal fatigue. An extensive simulation model is developed to validate the system reliability metrics accuracy. Numerical examples are presented to illustrate the use of the models.