A Nonlinear Combined High and Low Cycle Fatigue Model for Life Prediction Considering Loading Interaction

Aero‐engine turbine blades experience complex loading interaction under combined high and low cycle fatigue (CCF). Accurate life prediction is fundamental for ensuring the performance and safety of the components. This study investigates a nonlinear damage accumulation model based on the theory of damage equivalence and analysis of the damage accumulation process. A nonlinear CCF model is proposed by incorporating a new coupled damage term into the presented damage accumulation method, which addresses the interaction effect between high cycle fatigue (HCF) and low cycle fatigue (LCF). To rigorously validate the generalizability of the proposed methodology, experimental datasets encompassing three distinct alloy materials along with turbine blades are used for validation. The results demonstrate the enhanced approach exhibits superior prediction performance when subjected to CCF loadings.