The random fatigue-limit model in multi-factor experiments

Abstract

The Random Fatigue-Limit (RFL) model in Pascual and Meeker (1999a) was motivated by the need to describe fatigue life of certain materials. The RFL model describes the relationship between lifetime (measured in cycles) and a single factor, often the applied stress on the material. It has been found to be particularly useful for modeling high-cycle fatigue (HCF), that is, lifetimes that exceed 10 million cycles. Outputs from this model can be used as input for system models for lifetimes of jet engines for design purposes. Understanding how well parts hold up as a function of stress and other environmental variables would be valuable to engineers designing new and better engines. In this article, we show how the RFL model can be extended from single factor (single stress) to multi-factor situations. We fit the proposed model extensions to available data and describe methods to assess the adequacy of the fits.