Research on Analysis and Solution of Abnormal Vibration for EMU Carbody

Abstract

Recently, the problem of abnormal vibration of the EMU carbody has occurred from time to time. When the carbody is abnormally vibrated, the Sperling index and ride comfort of the vehicle can be greatly reduced, which is unfavorable for its operation. The paper established and a vehicle-shake simulation model which was verified based on the measured wheel-rail profile and vibration data. Additionally, the causes and solutions of abnormal vehicle body vibration were studied. The research results illustrate that the EMU has a relatively high level of wheel-rail equivalent conicity in the shaking section, causing the secondary hunting instability. The main frequency of the instability is 9-10 Hz, which is close to the first-order diamond mode frequency of the carbody. Therefore, the elastic resonance of the carbody occurs, resulting in the shake phenomenon. Through simulation analysis, it is found that wheelset reprofiling and rail polishing can improve the operation stability of EMUs and effectively solve the shaking motion; Furthermore, increasing the first-order diamond mode frequency of the carbody and controlling the hunting phase of the front and rear bogies can also avoid the shaking motion. At the same time, the equivalent conicity management through the detection of the wheel profile can efficiently prevent the hunting instability and carbody shaking, providing a reference for wheel reprofiling and rail polishing.