Contact Theoretical Modeling And Simulation Analysis Of Rail Grinding Using Open Belt Based On Grinding Plate

Rail grinding is internationally recognized as an effective technology for track maintenance and repair,which can eliminate or delay various diseases on the rail surface,repair the rail profile,improve the wheel-rail matching relationship,extend the service life of the rail and improve the smoothness and safety of train operation.At present,the increasing railway load and heavy grinding tasks have put forward new requirements and challenges to the rail grinding quality and efficiency.Compared with the contact-wheel closed abrasive belt grinding,the open abrasive belt grinding based on the pressure grinding plate adopts the full profile copying grinding method,which is more suitable for the preventive high-speed grinding maintenance of the light disease line,especially the existing high-speed railway wave grinding.However,at present,the research on the contact mechanism of rail open abrasive belt based on pressure grinding plate is still very lacking,which to some extent limits the practical application of this new rail grinding method.For this reason,this paper makes an in-depth study on the grinding contact mechanism of rail open abrasive belt based on the grinding plate,so as to master the influence law of different grinding process parameters and the parameters of the grinding plate type on the contact stress.The main research contents are as follows:The contact relationship between the grinding plate,abrasive belt and rail is analyzed,based on st.vinan’s theory and Hertz’s contact theory,and combined with the hypothesis of small deformation,the contact theoretical model of the grinding plate,abrasive belt and rail of the open type abrasive belt of the rail is studied and established,and the shape of the contact area and the contact stress distribution are obtained.ABAQUS software is applied to the simulation calculation of rail open abrasive grinding under concentrated force,and the verification of contact theory model is realized.The contact stress under single concentrated force,uniform distributed load and multiple concentrated force were analyzed and compared.Based on the established single concentrated force finite element simulation model,ABAQUS software was used to analyze the contact stress on rail surface under uniform load,and the distribution of contact stress on rail surface under uniform load was obtained.Based on the analysis of the contact stress of multi-concentrated force application,the optimal position of multi-concentrated force application is position 5.By comparing the variances and ranges of the contact stress of rail section under the three application modes,the uniformity of the contact stress distribution was judged,and the optimal loading mode of grinding pressure was obtained.The finite element simulation of rail surface contact stress was carried out under different grinding pressure and plate shape parameters.The rail surface contact stress increased with the increase of grinding pressure,and the increase rate was 0.05 KPa /N,and the increase rate was from 7 KPa to 48.9 KPa with the increase of the slotted width of the grinding plate.Through the simulation analysis of dynamic contact stress,it is found that the contact stress on the rail surface fluctuates under dynamic condition,increasing first and then decreasing as a whole.This study can provide support for the selection of grinding pressure and the design of the parameters of the grinding plate.