Study On Vertical Coupling Vibration Of Low-Medium Speed Maglev Train-Bridge System

Following our country’s rapid increase of economy and the acceleration of urbanism process, available space in the city is become much more precious. And the pressure on the traffic systems is tremendous because of the rapid growth of population. The maglev train which has a large climbing gradient, small swerving radius, low noise, no pollution and can be compatible with any circumstances is clearly one of the ideal traffic systems to solve this problem in the future. Considering the characteristics of traffic in city, the future market of maglev train system will be very broad. Based on this background, the article carry out the study on coupling vibration of low-speed maglev train-bridge system.Considering the function of electromagnetic force and track irregularity, a simulation analysis program of low-speed maglev train-bridge coupling vibration named VIMTB is written in the engineering background of the low-speed maglev test line of Zhuzhou locomotive factory. The reliability of the program has been confirmed by field test. Then, with the help of program VIMTB, the dynamic responses of a simply supported beam with20m span and a three span continuous beam adopted in the low-speed maglev test line of Zhuzhou locomotive factory is analyzed, and the factors affecting the impact effect of the simply supported beam bridge are also studied. In the end, the dynamic performance of the simply supported beam bridge is tested by field trial. The conclusions are described as follows:1. Compared with the field test data, the calculation results of program VIMTB is credible.2. Simulation results show that, the dynamic performance of the simply supported beam bridge meets the requirement. Maximum deflection and acceleration values are increased with the increase in speed. For the maglev train, its displacement goes greater while its weight is added, and its dynamic response value increases with the increase in speed. The air spring between car body and suspension frame plays a big role in isolation of vibration. And the variation amplitude of suspension clearance increases with the increase in speed.3. The dynamic coefficient of bridge is smaller than1.10when the maglev train’s speed ranges from10km/h to80km/h. The dynamic coefficient value increases with the increase in speed but decreases with the increase of bridge’s damping ratio. And the coefficient also increases with the increase in vehicle’s weight. 4. The field test data shows that, the dynamic responses of simply supported beam with span of20m increase with the increase in speed. The bridge’s stiffness and dynamic performance can meet the requirements of specification. Besides, the smooth operation of maglev train is not very good while the speed ranges from5km/h to10km/h. In the future we should pay more attention to the stability of suspension control while the vehicle’s speed is very low.