Experimental and numerical study on bogie hunting motion of metro vehicles induced by wheel concave wear

In the long-term operation of metro vehicles, the obvious concave wear of the wheel profile will occur and will lead to poor wheel-rail contact conditions. Consequently, the bogie hunting instability arises and the bogie hunting motion would be excited under certain excitation, leading to the abnormal vibration phenomenon in metro vehicles. This paper presents experimental and numerical research on the bogie hunting motion of metro vehicles induced by wheel concave wear. The features of the abnormal vibration and wheel concave wear of a metro vehicle are revealed through comprehensive field tests. A three-dimensional metro vehicle-track coupled model is established to investigate the mechanism of the bogie hunting motion resulting from the wheel concave wear. The influences of the wheel concave wear and the operating speed of the metro vehicle on the bogie hunting stability are discussed. The results show that the bogie hunting motion resulting from the wheel concave wear is the root cause of the abnormal vibration of the metro vehicle. Re-profiling the wheel profile and reducing the operating speed of the metro vehicle can significantly eliminate the abnormal vibration phenomenon.