Dynamic Monitoring and Evaluation Index of Metro Wheel Polygonal Wear

［Objective］Metro wheel polygonal wear causes vehicle vibration, affecting the smoothness and comfort of the vehicle operation. The existing static detection methods for wheel out-of-roundness consume a lot of manpower and material resources, a dynamically monitoring for the wheel polygonal wear severity is required. ［Method］A dynamic simulation model of whole-vehicle rigidity and sub-rail foundation flexibility is established; a wheel polygonal order characteristic analysis method based on rail vibration acceleration is proposed; the wheel polygonal wear evaluation index is analyzed and verified based on measured data. ［Result & Conclusion］The wheel polygonal degree index K is less affected by track irregularity and can quantitatively reflect the degree of wheel out-of-roundness; the wheel polygonal amplitude calculated based on the evaluation index K has better consistency with the actual wheel circumferential radial runout amplitude.