Simulation And Experimental Study On Chip Formation Mechanism Of U71Mn Rail Grinding

Steel rail is an important part of the train operation track,which directly affects the safety and efficiency of the train operation.The acting force between the wheel and the rail is complex.A series of damage will occur in the rail under long-term operation.Rail grinding is an effective means to remove the rail damage.During the rail grinding process,the grinding sand wheel and the rail action mechanism is complex,affecting the grinding efficiency and grinding quality.Therefore,the mechanism of rail grinding is studied by using the method of finite element simulation and experiment.The specific research contents are as follows :(1)Analysis of the basic theory of single abrasive cutting,focusing on the physical process of single abrasive cutting,theoretical analysis and relevant formula derivation of contact arc length,cutting force,chip thickness,cutting heat,scratch length and material removal rate in the cutting area of single abrasive cutting provide theoretical guidance for the simulation and experimental work of the paper.(2)The geometric model of single abrasive particle is determined according to the geometric characteristics of abrasive particles on the surface of grinding wheel,and the finite element model of single abrasive particle cutting is established ABAQUS using finite element simulation software,and the simulation of single abrasive particle cutting is carried out.The material deformation and stress distribution of cutting process and the influence of different cutting parameters(cutting speed,cutting depth,cutting edge front angle)on cutting force,chip morphology and cutting temperature are studied and analyzed.(3)According to the distribution of abrasive particles on the surface of grinding wheel,the geometric model of multi-grinding wheel is created,and the finite element model of multi-grinding grinding is established ABAQUS using finite element simulation software,and the simulation of multi-grinding is carried out.The mechanism of rail surface formation were studied.(4)Design and manufacture of a single abrasive cutting experiment device and build an experimental platform on a high-precision five-axis tool grinding center.Based on the principle of single variable,the experimental scheme of single abrasive cutting is designed.Leica microscope was used to observe the scratch morphology,and the effects of different cutting parameters(cutting speed,cutting depth,feed speed)on the scratch bottom surface morphology,lateral material stacking width,lateral maximum uplift height,material removal rate were studied and analyzed.In this paper,by combining simulation with experiment,the cutting deformation and chip morphology of single abrasive cutting process are studied,and the mechanism of rail grinding chip and the influence of different process parameters on cutting process are explored.The conclusion has certain reference significance for improving rail grinding process,improving grinding efficiency and grinding quality.