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Vibration Characteristics and Transmission of High-speed Track Structure

： With the rapid development of high-speed railway, ballastless slab track is widely used. By using finite element analysis software ANSYS and multi-body dynamics software SIMPACK, a vehicle-flexible track coupled dynamic model is established. The safety and stability of vehicle operation are analyzed and the displacement, acceleration, acceleration power spectral density, load characteristics of the track system are studied. The effects of different speeds on the track vibration and the main influencing factors of the system vibration are also studied. The results show that the vertical vibration displacement, acceleration and load of the track structure decrease from top to bottom, and the attenuation amplitude from rail to track plate is larger than that from slab to base; the vibration energy of the track system is mainly concentrated in the range of 0-150 Hz, while the rail vibration energy more than 300 Hz is basically not transmitted downward through the fastener attenuation, and peaks of power spectral density shift to the right with the speed increases; when the vehicle runs at the speed of 300 km/h, the peak frequencies of the rail vertical acceleration power spectral density less than 100 Hz are mainly related to the rail natural property, and peak frequencies greater than 100 Hz which present multiple relationship are related to the inherent property of track system. The co-simulation improves the research efficiency and the vertical vibration characteristics and transmission law of vehicle track system are revealed which provide a scientific evidence for engineering application.