A general method for determining probabilistic S-N curve based on static strength data of material

摘要

The conventional group test method for obtaining probabilistic S-N curve is a time-consuming and expensive test program. This study aims to present an alternative method for determining the probabilistic S-N curve of material based on its static strength data. Firstly, the probabilistic mapping relationship between the static strength and fatigue life of material is elaborated. Subsequently, the Weibull distribution is utilized to model the static strength and fatigue life data of material, and the correlation between the distribution parameters of them is investigated. Finally, an alternative method for determining the probabilistic S-N curve of material is proposed, and the experimental data of carbon steels and composite laminates are applied to verify its validity. The results show that the proposed method is capable of determining the probabilistic S-N curve of material based on its static strength data, which can significantly save test time and reduce test cost. In engineering applications, when the parameters of static strength distribution and the median S-N curve are known, the probabilistic S-N curve with any given survival probability can be determined through a unified analytical expression.