Fretting fatigue life model and validation of curvic coupling structures based on friction work threshold regulation

To address the complex failure mechanisms and prediction inaccuracies associated with aero-engine curvic coupling structures, this study develops a multiaxial damage-coupled model that integrates critical plane energy parameters with friction work threshold regulation. A life prediction equation is formulated by incorporating a friction work threshold parameter, thereby accounting for the competing effects of fretting wear and crack propagation. A high-temperature mechanical loading apparatus, based on a stress ring, is designed to facilitate experimental validation, and the accuracy of the proposed life prediction model is confirmed using representative simulated specimens. The regulatory influence of the friction work threshold on damage modes is also verified. The findings present a novel methodological framework for fretting fatigue life design in rotor systems of aero-engines.