Simulation Study On The Influence Of Wave Wear Characteristics On Wheel Rolling Contact Fatigue Crack Growth

The wheel is subject to rolling contact fatigue loads between the wheel and rail.Once the rail wears,the wheel-rail contact stress will be increased,which will seriously affect the wheel life.Therefore,when the rail corrugation reaches a certain level,it needs to be polished to eliminate the adverse effects of corrugation.But there is still no scientific theoretical support for the formulation of rail grinding standards at present.In this thesis,the wheels of CRH2 high-speed trains with peeling damage are taken as the research object.The evolution characteristics of surface cracks are analyzed experimentally,and combined with their service conditions,a joint simulation of ABAQUS and FRANC 3D software is carried out.This thesis discusses and reveals the influence of the rail wear characteristics(wave depth and wave length)on the crack propagation behavior of the wheel surface and wheel life.The main research contents and achievements of the thesis are as follows:Firstly,through investigation,we learn the main characteristics and control requirements of the rail corrugation at home and abroad,clarify the research status of the rail corrugation on the wheel rolling contact fatigue,familiarize with the current rail grinding standards,and determine the research content and research methods.Secondly,the peeling failure analysis of the CRH2 high-speed train wheels is completed,and the propagation behavior of surface cracks inside the wheels is clarified,that is,the crack arc gradually expanded around the crack source as the center;the location of the cracking initiation,which is 3 mm away from the surface of the wheel tread about.In addition,the performance test of the wheel steel material is carried out in this thesis,which provides data support for the construction of the simulation analysis model.Then,based on the ABAQUS software,this thesis discusses the effect of wave grinding characteristics on the rolling contact stress of wheels,and clarifies the influence law of the wave grinding characteristics on the rolling contact stress.When the wave grinding wavelength is constant,the rolling contact stress of the wheel becomes larger as the wave depth increases;when the wave grinding wave depth is unchanged,the rolling contact stress of the wheel increases first and then decreases as the wavelength increases.Finally,this thesis uses FRANC3D software combined with the results of wheel peeling damage failure analysis to reveal the effect of rail wave grinding characteristics on the internal crack propagation behavior and wheel life of the wheel.When the wave grinding wavelength is constant,the wheel life decreases as the wave depth increases;when the wave grinding wave depth does not change,the wheel life decreases first and then increases as the wavelength increases;wheel fatigue cracks are in rolling contact under the action of load,mainly the type II and type III crack propagation,the life of the initial crack growth stage accounts for the main part of the total expansion life.The above simulation results are consistent with the test results.The research results of the final thesis provide a certain theoretical basis for the development of rail grinding standards,and also have a certain engineering application value.