Flexible vibration of rail vehicle car-body induced by out-of-round wheels

The flexible resonance vibration of rail vehicle car-body could be excited by out-of-round (OOR) wheels when the wheel load impact frequency coincides with any of the car-body flexible mode frequencies. This paper presents an investigation of the flexible resonance mechanism of a metro vehicle car-body caused by OOR wheels. The characteristics of the flexible resonance vibration of a metro vehicle and the wheel OOR wear are reported based on comprehensive field tests. A vehicle-track coupled dynamics model considering the flexible car-body is established and applied to reproduce the abnormal resonance vibration of the metro vehicle. The resonance mechanism of the vehicle car-body flexible vibration caused by the OOR wheels is revealed through extensive simulation analysis. The influences of wheel wear states on the car-body flexible resonance vibration are investigated in detail. The results show that the car-body flexible resonance vibration excited by the OOR wheels is the root cause of the abnormal vibration and ride comfort reduction of the metro vehicle. The vehicle load and track conditions also influence the abnormal vibration response of the metro vehicle. The flexible resonance vibration can be minimised when the wheel wear differences of a rail vehicle are controlled.