Analysis Of Temperature Effect On High-speed Maglev Superposed Guideway Under Sunshine

Maglev vehicle system is an innovative ground transportation with great development prospect,which could become the fastest rail transit in the word.However,the high cost and complex construction of guideway has restricted the development of super-high speed maglev,causing that there is no maglev project with a speed over 600 km/h at home and abroad.To address these issues,a superposed guideway is put forward,and the structure form of this new guideway is studied.Meanwhile,the 3-D temperature field and temperature deformation are studied to provide a reference for practical engineering.In this paper,based on the assumption in dimensions of superposed guideway,the shear resistance,deflection-span ratio and the fundamental frequency of high speed maglev guideways were checked.The influence of connection strength on guideway stiffness was studied,and the results show that the size and height of the connection have a certain influence on the stiffness,while the position of the connection member has almost no influence.Recently,the temperature effect of guideway is concentrated on the cross section temperature field,which is not suitable for girder with variable section like superposed guideway.The 3-D temperature field of the girder simulated by the finite element method was compared with the experimental data of existing papers,so that the finite mode established here was validate.The 3-D temperature field and temperature deformation of superposed girder were analyzed,and then the results were compared with those of the whole box girder.The results show that the influence of section variation on temperature field of the connection is considerable,while insignificant for other components.Under the action of sunshine temperature difference,the beam type of superposed girder has a great influence on the vertical temperature deformation,while hasa little influence on the transverse temperature deformation.The influence of the height,size and position of the connection on its temperature deformation was studied.It is found that the height of the connection has little effect on the temperature deformation and temperature field of the superposed beam.The larger the area of the connection is,the greater the influence on the temperature field of the connection member and its surroundings is and the smaller the vertical maximum temperature deformation is.The change of the position of the connection has no effect on the temperature deformation of the superposed guideway.