Recent progress in the application of multiaxial fatigue criteria to lifetime calculations

Abstract

This paper presents the concept of life-dependent material parameters applied to multiaxial fatigue damage models. Every multiaxial fatigue limit criterion based on the history of the stress tensor components is defined by a scalar parameter that is compared with the fatigue limit. The defined damage parameter is usually also a function of some characteristic material parameters. These material parameters are usually derived from fatigue limits obtained under uniaxial and torsion loading. Attempts to extend this classic form of the damage parameter beyond the fatigue limit domain, i.e. to lifetime calculations, fail even within the high cycle fatigue domain. The aim of this paper is to demonstrate that the material parameters derived from fatigue limits should not be applied in multiaxial fatigue criteria for lifetime calculations. A definition of these material parameters based on applying fatigue uniaxial and torsion characteristics instead of fatigue limits implies that the resulting parameters are functions of the fatigue life. Applying a life-dependent material parameter to the Matake multiaxial fatigue criterion leads to a remarkable improvement in the fatigue life prediction for 2124-T851 aluminium alloy.