Modeling And Simulation Research On The Temperature Field Of Abrasive Belt Grinding On The Surface Of Wavy Abrasive And Cracked Rails

Steel rail is an important basic component of rail transportation,because of its openair service environment and complex working load,it will inevitably produce various kinds of damage and defects such as wave wear,crack,stripping,fat edge,etc.in the service process,which seriously affects its service life and train operation safety.As a new type of rail maintenance technology,abrasive belt grinding has the advantages of high efficiency grinding and cold grinding,but for the grinding of wave grinding and crack coexisting rail surface,the technology still faces the problem of white layer or burned blue on the rail surface,which indicates that there is a high instantaneous high temperature in the grinding process,which is prohibited by the grinding quality acceptance standards.For this reason,this paper aims to grasp the law of rail surface temperature change when grinding wave grinding and cracked coexisting rails,and conducts research on the change law of rail surface temperature with grinding depth,feeding speed and grinding direction during closed belt grinding process,the main research contents are as follows.(1)Based on Hertzian contact theory,circular contact heat model,heat transfer and virtual heat source method,the theoretical models of temperature field during abrasive belt grinding of wave grinding rail surface and wave grinding and cracked rail surface were established respectively,and the thermal coupling simulation model of temperature field during abrasive belt grinding of wave grinding rail surface was also established.Compare the calculation results and simulation results of wave grinding rail surface grinding,found that the two in the temperature change trend,temperature distribution and temperature size and other aspects of the basic match,to verify the reasonableness of the simulation model,for the subsequent development of the simulation test to explore the law of temperature field changes to provide the basis.(2)Using simulation means to investigate the influence of wave mill morphological parameters and grinding process parameters on the rail surface temperature field when grinding wave mill rail surface,grasp the grinding wave mill rail surface temperature distribution,time-varying temperature peak and grinding the highest temperature with wave mill morphological parameters and grinding process parameters,and get the grinding position of coexisting rail surface simulation experiments.Based on the multivariate nonlinear fitting,the prediction formula of the maximum grinding temperature under different wave grinding morphology parameters and grinding process parameters is obtained.Through the variance analysis of the formula,the wave grinding morphology parameters and grinding process parameters with the greatest influence on this temperature are clarified,which provides the theoretical basis for the formulation of the wave grinding dressing plan.(3)Combining the variation law of grinding temperature field under the wave grinding rail surface with the variation law of rail surface temperature when grinding cracks obtained in the laboratory,a thermal coupling simulation model of the temperature field when grinding the rail surface with cracks was established based on the wave grinding and coexisting rail surface,and investigating the influence of grinding depth,grinding speed and grinding direction on the temperature field of the rail surface,and mastering the temperature distribution,time-varying temperature peak when grinding the coexisting rail surface The temperature distribution,time-varying peak temperature and maximum temperature of grinding with the grinding process parameters were found to be significantly different between grinding the coexisting rail surface and grinding the wavegrinding rail surface.Through the ANOVA of the fitted maximum temperature,the grinding process parameters with the greatest influence on the maximum grinding temperature were obtained.It provides a theoretical basis for the selection of grinding depth,feed speed and grinding direction for abrasive belt grinding of wave grinding and cracked coexisting rail surface...