Simulation Study On Microstructure-Performance Evolution Of Load-Bearing Area Of High-Speed Train Axle Box Bearing

In the era of rapid development of high-speed train,people pay more attention to the safety of its operation.Axle box bearing is a very important part in the operation of high-speed train,its performance directly affects the safety of train operation.With the development of highspeed train to high speed and heavy load,the load condition of axle box bearing becomes more and more complex,which limits the implementation of related experimental research.Therefore,the dynamic characteristics of load-bearing area are studied by combining macro simulation with micro simulation,that is,through the stress simulation analysis of load-bearing area under different working conditions,the weak position of load-bearing area is found,and the evolution mechanism of crack and spalling damage in load-bearing area is analyzed,the specific research work is as follows:(1)Taking the double row tapered roller bearing of high-speed train as the research object,the finite element simulation numerical model is established by using ANSYS / LS-DYNA dynamic analysis software.The dynamic characteristics of load-bearing area under different speed and load conditions are analyzed,and the high stress area which is easy to damage in bearing area is found through the distribution of stress field.The simulation results are compared with the theoretical values to verify the effectiveness of the simulation model.The results show that the upper half of the bearing is obviously load-bearing area,and the bearing area of the rolling element with azimuth angle of 0 degree in the load-bearing area is the largest,and the load-bearing area expands with the increase of radial load and axial load.(2)According to the stress distribution on the raceway surface of tapered roller bearing,the location of fatigue crack on the raceway surface of the outer ring is determined,and the finite element model of fatigue crack on the raceway surface of the outer ring is established.The distribution of stress field at the raceway surface crack is studied.The evolution process of microstructure along the depth direction of raceway crack is simulated by DEFORM-3D software,the evolution law of fatigue crack of rolling element under load is analyzed.(3)Using ANSYS / LS-DYNA software,the dynamic simulation of load-bearing spalling damage model is carried out,and the dynamic and kinematic behaviors of bearing components are analyzed when there is spalling damage in the load-bearing area.The results show that the spalling of different parts causes the acceleration of the rolling element to change dramatically and the contact stress to increase.In addition,the maximum stress of the bearing increases significantly when all parts are spalling.Through the multi-scale research method of combining macro and micro simulation,the dynamic characteristics and microstructure evolution mechanism of bearing damage area are obtained.The research results of this paper will provide a theoretical basis for independent research and development,manufacturing and failure prevention analysis of bearings.