Critical Plane Concept and Energy Approach in Multiaxial Fatigue

Abstract

This paper aims to propose a new interpretation of several energy based critical plane high cycle fatigue criteria. More exactly, the meaning of several global energy based criteria is detailed from the calculation of normal and shear work on a critical plane. This study is limited to multiaxial fatigue under constant amplitude and synchronous loadings (proportional or non-proportional), with or without mean load. After a short review of some energy based criteria using the critical plane concept or a global approach, the reasons why energy based critical plane criteria are more and more developed in literature are summarized. It is shown that a direct link exists between critical plane energy parameters and global ones. A critical examination of the famous Findley et al. experiments is proposed and the previous link is illustrated with two mesoscopic criteria developed by Papadopoulos and the global energy based criterion of Banvillet et al. This leads to propose an interpretation of fatigue crack initiation from the mesoscopic scale up to the macroscopic scale either with stress and strain quantities or with strain energy parameters.