Multiaxial fatigue life prediction model for notched specimen based on modified energy gradient and critical plane method

Abstract

The distribution of energy field on the crack initiation plane directly affects the crack initiation behavior. Therefore, studying the energy gradient is of crucial help for accurate evaluation of the fatigue performance for the notched specimen. Firstly, the energy distribution on the critical plane is characterized by the sixth-order polynomial. Meanwhile, the relative energy gradient is adopted to calculate the critical distance. Secondly, considering the influence of energy gradient, size effect and non-proportional additional strengthening, a general procedure is explored. Finally, the experimental data of Al7050, En8 and C40 is utilized for model validation and the comparison results show that prediction results of the proposed model in this paper is superior to other models.