Application of the Multiaxial Fatigue Life Prediction Model Suitable to the Key Components of Aeroengine Considering the Effect of Non-Proportionality

Current multiaxial fatigue models have demonstrated satisfactory performance in predicting fatigue life under various loading paths. However, they often exhibit limitations that restrict their ability to accurately predict the fatigue life of real-world structures. This study proposes a new definition of non-proportionality based on the proposed octahedral stress and energy method for predicting multiaxial fatigue life. In the model, both non-proportionality and the damage parameter are applicable to tensor space, ensuring broad generality and applicability across diverse scenarios. The predictive performance of the new revised model was compared with that of five widely used models using experimental data from seven materials reported in the literature, as well as experimental data from three materials obtained in this study. The results demonstrate that the new model achieves high accuracy.