Simulation And Analysis Of Temperature Field For Rail Grinding With The Open Abrasive Belt Based On Thermal-mechanical Coupling

Rail grinding is currently recognized as an effective technology for rail maintenance in the world.It can remove or control all kinds of rail defects,generate or restore rail target profile,improve wheel rail matching relationship,inhibit rolling contact fatigue,so as to greatly extend the service life of rail,improve the running stability and safety of train,and save comprehensive maintenance costs.As a new type of rail grinding technology,open abrasive belt grinding has the characteristics of fast grinding speed and high grinding efficiency,which is especially suitable for the treatment of rail corrugation.However,due to the commonly used type of grinding plate,a lot of heat will be generated in the grinding area,which will cause the rail surface temperature to rise or even be too high,and then cause rail burn and damage to the grinding tools.Therefore,this paper studies the grinding temperature field of rail open abrasive belt from the perspectives of grinding process parameters,structure of grinding plate and joint operation of multiple grinding units.The main contents are as follows:Based on the principle of rail open abrasive belt grinding,combined with the existing grinding car design scheme,the rail open abrasive belt grinding process is briefly introduced.On this basis,the heat transfer model of rail open belt grinding is established,and the heat transfer analysis is carried out.This paper discusses the mathematical solution strategy of the temperature field,puts forward the finite element calculation method of the thermal coupling of the rail open belt grinding process,which lays a theoretical foundation for the subsequent establishment of the thermal coupling simulation model and parameter analysis of the rail open belt grinding.For a single belt grinding unit,a thermal coupling simulation model of rail open belt grinding is established,and the temperature field in the grinding process is simulated and analyzed.On the premise of not affecting the simulation results as much as possible,the grinding unit and rail model are simplified as necessary,which are imported into the finite element simulation software ABAQUS,the material properties and boundary conditions are defined,and the grinding process parameters are input for simulation.The temperature field distribution of rail surface and the temperature change of grinding process are obtained.Through the simulation analysis of different grinding process parameters,the influence of different grinding pressure,grinding speed and pressure distribution mode on the distribution of rail surface temperature field and the maximum temperature is discussed.By changing the key parameters of the grinding plate,the influences of the number and width of the grooves on the distribution of the rail surface temperature field and the maximum temperature are analyzed and revealed.Based on the distribution of grinding units in the existing rail open belt grinding trolley and grinding train,a thermo mechanical coupling simulation model of joint operation of multiple belt grinding units is established.The temperature field of rail open belt grinding process under specific conditions is simulated and analyzed from two aspects of changing the number of grinding units and the distance between grinding units,and the grinding speed is further discussed The influence of grinding temperature field of grinding unit.