An improved fatigue accumulation damage model based on load interaction and strength degradation

This paper presents an improved accumulation damage model which is closer to the actual conditions based on the Manson-Halford (M-H) model. The model considers both the effect of load interaction and the phenomenon of strength degradation of materials induced by loading history. In addition, a new logarithmic residual strength model is proposed and its accuracy is verified by two sets of strength degradation experimental data. Finally, five sets of experimental data under two-level and multi-level loadings are compared with the prediction results. It is shown that the improved model has better applicability and higher accuracy.