Analysis Of Dynamic Response Of The High-Speed Magnetic Levitation Railway Guideway Girder

Presently, high-speed magnetic levitation railway has been built in our country. Dynamic property of the guideway girder is a key problem for the high-speed magnetic technology. Since the domestic feasibility studies of long high-speed magnetic levitation railway lines are on the point of start-up, we cannot depend on the importation of the entirely foreign magnetic levitation technology. We should study this problem on the condition of our country. It has deep signification for building rational and economic magnetic levitation railway system in our country.Firstly, this thesis presents the correlative developing situation inside and outside China. Then, take the simplification on the system of magnetic levitation railway, and confirm three types of guideway girders, such as Shanghai magnetic guideway girder, integral concrete box girder and composite steel-concrete girder based on the criterion of magnetic levitation. Using finite element software ANSYS, the author builds the finite element models for three guideway girders, meanwhile, analyses free vibration by calculating the frequency and the mode. Lastly, the time history analysis of transient-dynamic .response and a series of contrast analysis are done under the moving load. On the base of dynamic equation, with the Newmark integral method, taking into account the influence of the moving load velocity, the dynamic response of the guideway girders are also discussed. Three types of velocities are considered, the highest speed, the service speed and the possible resonance speed. At the same time, the deflection time history graphs and the response stress graphs in mid-span section are given.From the time history analysis of transient-dynamic response, the dynamic response of guideway girder is very obvious. The dynamic deflection is much bigger than the static deflecion. Especially on the condition of high speed (the service speed of magnetic levitation train is 430 km/h), research on dynamic analysis of guideway girder is necessary. After analyzing the results of the calculation, this thesis presents some conclusions, which are applicable to the design of the guideway girder.