A modified nonlinear fatigue damage accumulation model

This paper presents a modified nonlinear fatigue damage accumulation model accounting for load interaction effects. The original model is based on physical property degradation of materials, from which the load interaction effects are ignored. However, the load interaction effects have a significant influence on the fatigue life. In the study, by analyzing five damage models, a load interaction parameter is obtained and added to the original model. Experimental work is then carried out to verify the modified model of four categories of experimental data from smooth and notch specimens under two-level stress loading. Moreover, comparison is made among the results calculated by the test data, the Miner's rule, the original model, and the modified model.