Fatigue Strength Analysis And Remaining Life Evaluation Of Rail Vehicle Wheels

As an important component of high-speed EMU,wheels play a vital role in ensuring the safety of trains.With the continuous development of technology,the speed and axle loads of trains are also increasing,and the conditions of wheels have become more complex,and the wheel fatigue problem has become more prominent.Many wheels develop small fatigue cracks after a period of operation,and if the wheels are blindly replaced,it will lead to a waste of manpower and resources,so how to maximize the value of wheels containing small cracks without affecting the safety of operation has become the focus of research at this stage.Therefore,it is particularly important to analysis the fatigue strength and assess the remaining life of the wheel.Firstly,a finite element model of a rolling stock wheel is established,and the wheel finite element model is loaded with reference to UIC 510-5 and BS EN13979-1 standards to evaluate the static strength of the wheel as a whole.The most dangerous fatigue conditions are determined by using the Haigh-Goodman criterion and the Crossland criterion for the fatigue strength assessment of the web and web hole hazard areas,respectively.Secondly,an elastic-plastic wheel-rail contact finite element model is established,and the real stress-strain data of the wheel-rail are used into the finite element model.The paper investigates the effects of different axle loads,lateral displacement,track cant and attack angle on the stress and PEEQ in the wheel-rail contact area,and analyzes the location where cracks are likely to occur after plastic deformation of the wheel rim from a mechanical point of view.The results show that the impact of attack angle on the stress in the wheel-rail contact area is the largest,followed by the lateral displacement,then the track cant,and the axle load has the least impact,the maximum stress and maximum plastic deformation occurs at2mm～3mm from the tread,which is also the location where rolling contact fatigue cracks often occur.Thirdly,a method is proposed for the failure assessment of the hazardous area of the wheel web and web hole,and the failure assessment of the hazardous area of the wheel web and web hole is carried out by combining the FAD diagram in BS 7910 standard,analyzing the safety of the hazardous area,determining the law of crack propagation,and determining the critical crack size according to the law of crack propagation.Finally,a finite element model of the wheel with cracked rim is established using ABAQUS in conjunction with FRANC3 D software,the stress intensity factor at the crack tip is analyzed,and the type of cracks at the rim is determined.The validity of the simulation model is determined by comparing the measured data with the simulated data,and the crack insertion is carried out based on the location where the crack tends to occur from the wheel-rail contact stress analysis,and its remaining life is calculated.In addition,the effect of initial cracks at different locations and sizes on the remaining life of the wheel is analyzed,and the damage tolerance value is determined based on the simulated crack extension life curves,and a method for calculating the damage tolerance values and remaining life is proposed for cracks at different locations and sizes.The research content of this paper provides guidance for the fatigue assessment of wheels without defects in the design phase and the calculation of the remaining life of wheels with defects in the service phase,which helps to improve the service life of wheels while ensuring the safe operation of wheels.