Research On Temperature Field Modeling And Simulation For Contact Area Of Rail Grinding With The Open Abrasive Belt

Rail grinding is an important way of railway maintenance.It is used to repair various diseases on the surface of rails,improve wheel-rail relationship,and extend the service life of rails.As a new type of rail grinding technology,open-belt grinding has the advantages of long grinding time,high speed and high efficiency.To this end,based on the rail grinding of the open abrasive belt,the temperature field of the grinding contact area is studied,the surface model of the belt and the abrasive belt grinding thermal coupling model are established.The influence of different grinding parameters on the temperature field of the grinding contact area is studied,which provides theoretical support for the setting of grinding parameters.The main research contents as follows:Based on the grinding principle of the rail open abrasive belt,combined with the existing grinding equipment design,the grinding unit such as the grinding plate is designed and the grinding plan is given,which laid the foundation for the simulation analysis of the later grinding temperature field.The theoretical analysis and numerical calculation method for the temperature field thermal coupling of the open belt grinding system are proposed.The heat transfer method of abrasive belt grinding and the typical grinding heat model are analyzed.The heat transfer boundary conditions and temperature field solution method of abrasive belt grinding were discussed.The finite element solution for large deformation dynamics of abrasive belt bending and finite element calculation method for thermal coupling in grinding process are proposed.By discussing the modeling method of the surface morphology of the abrasive belt,a modeling method based on APDL programming for the random distribution of abrasive grains on the abrasive belt surface is proposed.Theoretical study on the abrasive grain size and spatial arrangement of the belt surface,combined with the function relationship and the random vibration algorith in the space,the APDL program is programmed and imported into the finite element simulation software ANSYS to generate the abrasive belt model for the grinding contact area.It provides a model basis for the simulation analysis of the subsequent grinding temperature field.The surface topography of the real abrasive belt was measured by the shape instrument and compared with the model,which confirmed the correctness of the modeling method and the model.Based on the abrasive belt model,the bending process of the belt and the temperature field of the grinding contact area were simulated.Using the meshing software HYPERMESH to mesh the grinding unit,define the material properties and boundary conditions by LS-PREPOST,and import into the LS-DYNA to simulate the bending process of the belt,obtained a curved belt model and its surface stress and temperature distribution.The finite element simulation software ABAQUS was used to simulate the thermal coupling during the grinding process,and the temperature field distribution results of the overall grinding contact area are obtained,which provides a basis for the subsequent simulation analysis of different grinding parameters.Through the simulation analysis of different grinding process parameters,the temperature field distribution of the contact area during the grinding process of the open abrasive belt was obtained.The influence of different grinding pressure and grinding speed on the maximum temperature and the incoming depth of the rail surface was discussed.The temperature field distribution of the rail surface under different pressure modes was obtained by changing the distribution of the grinding pressure on the grinding plate.The grinding process of the three-slot and four-slot plates was simulated.The influence of the grinding plates with different slots number on the temperature field distribution and maximum temperature of the rail surface was analyzed.