A Study on the Effect of Wheel-polygonal Wear on Dynamic Vibration Characteristics of Urban Rail Vehicle Axle-box Bearings

The axle-box bearing (ABB) makes crucial influence on the operation of urban rail vehicles through supporting the weight of the vehicle and load, lubricating the axle neck, and reducing friction. However, wheel-polygonal wear (WPW) can compromise the stability of the vehicle by aggravating the axle-box vibration. This work aims to study the dynamic characteristics of ABB in the presence of WPW. On one hand, a vehicle-track coupled dynamics model with ABB and flexible wheelset is established. Onsite tests are implemented to validated the effectiveness of this model, and the significance of the first flexible mode are also researched. On other hand, the study also analyzes the influence of WPW amplitude and order on ABB by inputting WPW into the model at different vehicle speeds. The results indicate that the amplitude of WPW influences the axle-box vibration amplitude, with an increase in amplitude leading to an increase in vibration amplitude. However, the influence of the order of WPW is more complex due to the existence of resonance phenomenon. The findings of this study can guide the maintenance of wheel machining and repair in urban rail vehicles, providing reference and guidance for future research in this area.