Evaluation of an energy-based approach and a critical plane approach for predicting constant amplitude multiaxial fatigue life

A new energy-based approach for predicting constant amplitude multiaxial fatigue life is described. The approach is based on cyclic plastic and elastic strain energy densities and takes into account effects of stress-state and mean stresses. A wide range of test data is used to evaluate the approach as well as a critical plane approach based on maximum amplitude of shear strain modified by the maximum normal stress on the plane of maximum shear strain amplitude. Predictive capabilities of both approaches are found to be comparable, with some differences for certain types of multiaxial loading.