Advanced Fretting Fatigue Life Prediction Method for Naval Aerospace Application

Fretting fatigue is a complex damage mechanism caused by cyclic loading combined with microscopic relative motion between contacting surfaces. This stick-slip interaction results in localized plastic deformation, micro-crack initiation, and ultimately, fatigue failure. Debris formation, oxidation, and surface wear further complicate the damage process. Despite extensive experimental efforts, it remains challenging to capture the full spectrum of interacting phenomena—such as contact pressure variation, debris evolution, and microstructural effects - purely through experimental investigation and test data.Given this complexity, computational simulations have become essential for predicting fretting fatigue behavior and supplementing empirical observations. Traditional modeling approaches include continuum mechanics and crystal plasticity methods, which provide insights into stress distributions and microstructural responses. However, these models often fall short in handling evolving contact conditions, surface degradation, and unpredictable crack paths.To address these limitations, we propose a multiscale computational framework integrating Peridynamics (PD), Finite Element Method (FEM), Crystal Plasticity (CP), and kinetic Monte Carlo (kMC) simulations. At the macro-scale, PD is coupled with FEM to combine the global deformation efficiency of FEM with the fracture modeling strength of PD, especially useful for handling arbitrary crack initiation and growth at contact interfaces. At the micro-scale, PD is coupled with CP to model grain-level deformation, capturing heterogeneity in slip, lattice rotation, and grain boundary interactions. Fatigue Indicator Parameters (FIPs) such as accumulated slip and energy dissipation are used to correlate with experimental fatigue life data. At the nano-scale, debris evolution, adhesion, and oxidation are modeled via kMC, accounting for the stochastic nature of third-body layer formation and its effect on local contact conditions and crack initiation.By integrating these three modeling layers—PD-FEM, PD-CP, and kMC - our method offers a comprehensive simulation capability that spans from global structural response to localized microstructural and environmental damage processes. This enables a transformative step forward in the predictive modeling of fretting fatigue life under complex real-world loading and environmental conditions