Fatigue Reliability Modeling Using an Energy-Based Parameter by Loading Cycle-Failure Life Interference: Validation and Application

Several probabilistic fatigue evaluation models have been proposed, but the effectiveness and accuracy of current models have not yet been examined. In this work, probabilistic fatigue life is linked to an energy-based damage parameter, where the statistic of logarithmic fatigue life is represented by this parameter. Taking into account the variability in loading amplitudes and material properties, a novel fatigue reliability assessment method for structural system is proposed, based on the probabilistic fatigue model and loading cycle-failure life interference principle. A series of strain-controlled fatigue tests of Inconel 718 alloy are conducted for model development and fatigue data with different strain ratios are collected from open literature to verify the model applicability. The results show that the proposed model aligns most closely with experimental data when compared to traditional probability-strain-life models, Xie’s modified model, Castillo’s model, and Correia’s model. Furthermore, a turbine fir-tree attachment is taken as an instance to illustrate the implementation procedure for fatigue reliability analysis. It is evident that the proposed method mitigates the overly conservative estimates typically provided by independent treatments in structural system reliability assessments. This research proposes a method for accurate evaluations of material-level fatigue life and system-level reliability supports reliability-centered design and life management of crucial structures.