| description abstract | Abstract. Rolling bearings undergo progressive degradation during service, where localized raceway defects evolve from initial pitting to extended wear, often exhibiting asymmetric defect-edge geometries and shoulder formation. Such geometric evolution plays a critical role in failure development but is inadequately represented in conventional dynamic models based on rectangular or idealized defect assumptions, limiting their ability to explain failure-induced vibration responses observed in practice. This study develops a physics-based dynamic model to investigate the failure mechanisms associated with asymmetric edge-wear evolution of raceway defects. The model explicitly incorporates evolving edge profiles and shoulder geometries through piecewise displacement excitation functions, enabling a mechanistic description of rolling-element motion and transient contact interactions across different defect regions. A direct relationship is thereby established between defect morphology, transient contact forces, and vibration responses. The proposed model is validated using finite element simulations of contact forces and experimental vibration measurements under defective conditions. Results show that neglecting defect-edge evolution leads to systematic overestimation of impact severity in rectangular defect models, whereas edge steepness and shoulder height dominate transient impact intensity and vibration persistence. These findings explain why defects of identical length can produce markedly different vibration amplitudes. By clarifying the role of defect geometry in failure-related dynamics, this work provides a mechanism-oriented interpretation of bearing vibration behavior and offers quantitative parameters for vibration-based fault diagnosis, defect localization, and prognosis, contributing to improved bearing health monitoring and reliability assessment. | |
