A unified multiaxial fatigue damage model for isotropic and anisotropic materials

A unified multiaxial fatigue damage model based on a characteristic plane approach is proposed in this paper, integrating both isotropic and anisotropic materials into one framework. Compared with most available critical plane-based models for multiaxial fatigue problem, the physical basis of the characteristic plane does not rely on the observations of the fatigue crack in the proposed model. The cracking information is not required for multiaxial fatigue analysis and the proposed model can automatically adapt for very different materials experiencing different failure modes. The effect of the mean normal stress is also included in the proposed model. The results of the proposed fatigue life prediction model are validated using experimental results of metals as well as unidirectional and multidirectional composite laminates.