Study On Temperature Distributions And Thermal Effects Of Maglev Guideway

In this paper, temperature distributions and thermal effects of the box-girder with different span-types are studied on the basis of Shanghai Maglev Rail System in complex climatic conditions such as solar radiation and temperature variation.First of all, the essential datas of Shanghai Maglev Rail System and the present research progress on box-girder thermal effects are introduced, and then the significance and main contents of this research are listed.Secondly, the basic theory of heat conduction in box girder is studied and all the factors affecting temperature distributions of maglev guideway are analyzed, including the basic parameters (such as concrete density and specific heat coefficient, etc.), the temperature conditions (such as solar radiation and temperature, etc.) and heat transfer factors (radiation absorption coefficient, wind speed, etc.) and so on. At last, the selection rules of various parameters are determined.In the 3rd chapter,the cross-section model of maglev guideway for transient analysis of temperature distributions is established using Ansys (finite element analysis software) and the temperature field is recorded at different times. And then the distribution laws are summarized to provide datas for further research.Deflection equations of maglev guideway with diffirent span-types are established to get the maximum values based on the calculation of the temperature field in the 4th chapter. The results show that span-type effects the deformation of box-girder is obvious, and increasing the number of spans is conducive to control the temperature deformation.Finally, simplified formula for calculating the temperature gradient is advised based on the numerical simulation of box girder referencing to Norms of different countries. In order to know the specific effects to temperature distributions and girder deflections , the parameters of temperature field are studied including wind speed, radiation absorption coefficient, temperature and so on, then the most adverse conditions are determined.