A historical and mathematical review and revision of the MultiStage Fatigue (MSF) model

Abstract

This work reviews the history and development of the MultiStage Fatigue (MSF) model since the inaugural work of McDowell et al. [1] in 2003 and presents a revised model that integrates the improvements and additions made over the past two decades. The MSF model is a physically based model that combines the multiscale, heterogeneous microstructures with the considered boundary conditions of a structural component in order to predict fatigue life performance. As such, a hierarchy of fatigue sensitivities can be determined for the microstructures of a given material, providing insight to the material’s structure–property relations. Given that microstructures are a direct result of processing methods, the MSF model is part of a greater paradigm to design performance-specific components following a chemistry-process-structure–property-performance logical flow. Since McDowell et al. [1], the MSF model has been used for a broad range of materials, processing methods, and life-cycle performance environments with some key enhancements and abstractions added by various authors all contributing to the model in its final form as it is presented herein. Therefore, this review also serves to consolidate the changes made over the past two decades and present a refined mathematical framework and nomenclature.