Wheel-Rail Profile Matching And Dynamic Performance Analysis Of Variable Gauge Vehicles In High-Speed Railway

With the increasing scale of cross-border and cross regional transportation,the use of variable gauge bogie technology for cross-border and cross regional transportation has the advantage of saving time and convenience.China’s demand for variable gauge vehicles is becoming increasingly urgent.However,the research on variable gauge bogies in China was carried out relatively late,and the technology is not yet mature.Currently,it is still in the experimental development stage.Therefore,the structural design,research,and wheel selection of various parts of the bogie are of great significance for reducing wear on key parts of variable gauge bogies,extending their service life,and improving the smoothness and safety of variable gauge vehicles.This paper classifies and summarizes the current research status of structural design and dynamic performance of variable gauge bogies both domestically and internationally,focusing on their contact performance and wheel rail profile matching.This article studies the effects of different gauge,wheel profile,wheel rail lateral displacement,wheel axle clearance,lateral force,and longitudinal force on the vertical contact performance of wheel axle rail,the lateral and longitudinal contact performance of wheel axle locking device,and the dynamic problems of variable gauge vehicles under different working conditions.The main research content and conclusions are as follows:(1)Research on the standard rail profiles corresponding to two types of track gauges,three commonly used standard wheel profiles in China,and a wheel pair locking mechanism scheme for variable gauge bogies.(2)Establish a dynamic model for the variable gauge high-speed high-speed train system,analyze the dynamic performance of different wheel profiles and different rail profile combinations under two gauge conditions,and comprehensively compare the straight-line running smoothness,curve negotiation performance,and wear number.It can be concluded that the XP55 type wheel has good dynamic performance and small wear under two gauge conditions.(3)Establish a finite element model for wheel axle rail multi-body contact,and calculate the effects of track gauge,wheel rail profile,wheel rail lateral displacement,and wheel axle clearance on the wheel rail and wheel axle contact performance of the straight line.The results show that the contact bandwidth of XP55 profile wheels is relatively large under both track gauges,and their wheel rail contact range is large,avoiding excessive concentration of wheel rail wear positions.When matching the standard wheel rail profile,the wear of XP55 profile wheels is relatively uniform under both track gauges.The change in track gauge has a relatively small impact on wheel axle contact,while the change in wheel axle clearance has a significant impact on wheel axle contact.As the gap between the wheel axles increases,the stress on the outer edge of the wheel seat increases,which can lead to fatigue cracks in the structure.(4)Establish a multi-body contact finite element model of the wheel axle locking device.The key structures of the model include a vertical and horizontal four pin hole structure for transmitting lateral force,a nested structure for transmitting longitudinal torque,a torque groove,and a torque block.Calculate the influence of track gauge,lateral force,and longitudinal moment on the contact performance of the wheel axle locking device.The results indicate that the locking device exhibits stress concentration at the edge of its hole.The edge of the contact part between the torque groove and the torque block,as well as the root of the torque block,has experienced stress concentration and may experience fatigue cracks due to significant stress.When using a 1520 mm gauge,the maximum equivalent stress generated by emergency braking on the vehicle exceeds the material yield limit.Comparing the contact performance analysis and dynamic performance analysis of different wheel rail profile matching at different track gauges,XP55 profile wheels have both good wheel rail contact performance and good dynamic performance,providing reference for the selection of wheel profile for variable gauge bogies.