Abstract: Vibration control of flexible car body of high-speed EMUs is of great significance for improving ride quality. Based on the contribution of elastic modal vibration of the car body, a method of precise elastic vibration control of the car body is proposed by using different existing suspension equipment as dynamic vibration absorber and designing suspension parameters of the equipment. Based on the modal superposition theory, a modal vibration decompositionm method based on singular value decomposition(SVD) and least square fitting is proposed, which decomposes the physical vibration of a railway vehicle car body into modal vibration is proposed, and each order modal vibration of the railway vehicle car body is decomposed. The contribution of different car body modes to the vibration of the installation positions of the equipments on or under the vehicle are analyzed. Based on this, the equipments are considered as dynamic vibration absorbers, and the target car body modes to be controlled by each equipment is determined. By using the natural mode method, the equivalent mass of the target vehicle body mode to be controlled at the installation position of each equipment is identified. Moreover, based on the dynamic vibration absorption theory, the vertical and lateral optimal natural frequencies and damping ratio of each equipment are designed, and the vibration control effect is verified by simulation test. The results show that the vibration reduction design based on dynamic vibration absorption can effectively reduce the vibration of the target modes and improve the ride quality of the railway vehicle. At the same time, under the optimal damping ratio of the equipment, the vibration of the equipments as dynamic vibration absorbers are not severe.

Key words: high-speed EMU, modal vibration decomposition, singular value decomposition, modal vibration control, dynamic vibration absorber