Three Dimension Contact Stress Analysis Of Axle-box Bearing Of High Speed Train

As the key transmission part of high-speed trains,axle box bearing has a complex service environment.With the increasing speed of high-speed trains,it will bear greater inertia force and vibration impact,and increase its fatigue damage.The main failure mode of bearing is contact fatigue damage,which shows random characteristics,and makes the contact problem of bearing become a complex three-dimensional random contact problem.At present,researches on bearings mainly regarded as an 2D axisymmetric model,the influence of contour defects is ignored.Therefore,it cannot explain the early local random damage.To solve this problem,this paper takes the random roundness defects into account,analyzes the mechanical properties of the bearing in the running state,completes the fatigue life analysis of the bearing,Provide a theoretical basis for the subsequent bearing fault diagnosis and repair of high-speed trains.The specific work is as follows:(1)Build 3D random outer surface profile and mechanical contact model.Analysis of the reasons for the randomness of the displacement and stress distribution of the bearing assembly according to machining characteristics.Convert a 2D axisymmetric model to a 3D random roundness model by Conformal piecewise cubic Hermit.Establish bearing contact mechanical model by load analysis and use of elastic mechanics.(2)Analysis of bearing displacement distribution and dynamic simulation.The effect of random roundness,different interference and tolerance levels on displacement is analyzed.According to the rotating inertial force and vibration of the bearing during actual operation,the dynamic simulation analysis is completed.(3)Research on early fatigue damage mechanism and fatigue life of bearings.Using rain flow counting to get simulation of stress spectrum statistics.Extrapolating the stress spectrum to get the 8-level stress spectrum of the bearing by Statistical method.Combined with the P-S-N curve and the Miner damage theory to complete the prediction of bearing life,provide a theoretical basis for the design and verification of the bearing.(4)According to the actual working conditions,the four bearings on the rolling vibration test bench are tested for the full life cycle,at the same time using acoustic emission for detection and analysis.According to the experimental results,the correctness of the random local damage mechanism of the bearing is verified,and at the same time it provides theoretical support for the study of bearing fatigue and fault diagnosis.