Research Of Fretting Damage In Press-fitted Part Of High-speed Wheel-axle

As the most important part of the high-speed train,the axle bears the weight of the entire vehicle.During the operation of the vehicle,the axles are subjected to periodic rotating and bending loads,and micro-movements will appear at the press-fitted part of wheel-axle.The fretting damage at the press-fitted part of the axle is one of the main reasons that the axles appear to be cracked and scrapped prematurely,which brings huge safety hazards to the operation of the train and the inevitable economic losses.In this paper,finite element simulations under the influence of fretting wear and fretting corrosion on the axle are carried out by user subroutines,the relevant design parameters of the axle(interference and overhang)are taken into consideration and simulation calculations are carried out under different working conditions.The main contents of this paper are as follows:(1)The existing two commonly used wear calculation models are Archard wear model and energy consumption method wear model.In view of the inapplicability of these two wear models based in macroscopic wear to finite element calculations,certain derivations and transformations are carried out to obtain the wear equation expression suitable for finite wear simulation calculation.Based on the transformed wear equation,the ABAQUS user subroutine UMESHMOTION is written to calculate the wear depth and wear direction of the nodes on the wear surface in the interference fit component.The ALE adaptive mesh technology is used to quantitatively update the coordinates of the nodes,so as to realize the post-wear characterization of the surface profile of the contact surface.(2)The user subroutines written based on the two wear models are used for the finite element wear simulation calculation of the interference fit structure of the shaft and the collar,and compare and verify the simulation results with the test results in the literature to determine the feasibility and accuracy of the user subroutines.Then further compare the simulation results of the two wear models and determine a better method for the simulation calculation of interference fit structure wear and full-scale structure wear of wheel-axle.(3)The better wear model for the simulation calculation of the interference fit structure wear is used in the simulation calculation of the fretting wear of the actual hollow wheel-axle press-fitted part,and in a variety of working conditions with different interference and different overhang.Following calculations are carried out to study the influence of interference and overhang on the fretting wear and fretting parameters at the press-fitted part of the wheel-axle.According to the simulation results,the values of interference and overhang for mitigating fretting wear are inferred.It is found that when the interference quantity is taken in the middle part of the design range and the overhang quantity is taken at the minimum value of the design range,the degree of fretting wear of the press-fitted part of the axle is the smallest.(4)Based on the consideration of fretting wear,the user subroutine was modified to realize the finite element simulation analysis of the hollow wheel shaft while considering fretting wear and fretting corrosion.According to the simulation results,the influence of fretting corrosion on the fretting wear and fretting parameters at the press-fitted part of the wheel-axle is studied.It is found that the stress distribution of the press-fitted part of the axle is changed and the material loss depth of this part increases sharply when fretting corrosion is considered.Figure 77,table 2,reference 72.