Analysis of vertical dynamic wheel/rail interaction caused by polygonal wheels on high-speed trains

In order to investigate vertical dynamic wheel/rail interaction resulting from a polygonal wheel at high-speeds, a vertical vehicle-track coupled dynamics model is adopted. The measured results from German ICE polygonal wheels are utilized as multi-harmonic excitations. Two types of out-of-round wheels, the periodic and the non-periodic, are simulated and compared. The dynamic wheel/rail interaction induced by different harmonics is analyzed in both time and frequency domains. Results demonstrate that the polygonal wheel will result in considerable fluctuation of wheel/rail contact force. Derivative of wheel radial deviations can effectively reflect dynamic wheel/rail contact force at train speeds above 300 km/h. Dynamic wheel/rail load becomes more sensitive to high order harmonics with increased speeds. Influence of the out-of-round wheel on vehicle system is mainly related to the wheelset vibration. Short-wavelength components of the polygonal wheel stimulate high-frequency vibrations of rails and sleepers.