Wheel-rail Dynamics Test And Simulation Study Of Common Speed Turnout

At present,the total mileage of normal-speed lines in my country accounts for about 74%of the total mileage of railway operations in the country,and it occupies an important position in railway transportation.As an important part of railway lines,turnouts play the role of connecting two tracks and crossing crossing lines.Due to the variable cross-section characteristics and plane geometric parameters of the track structure in the turnout area,which are different from the general lines,the wheel-rail relationship is more complex,the dynamic response is more significant,and the safety problem is more prominent when the train passes through.weak link.In this paper,the corresponding research work is carried out on the No.12single turnout of the general-speed line.Combined with the data collected from the dynamic test of the switch area and the simulation results of the vehicle-turnout coupling dynamics,the stability and operation safety of the train before and after the rail grinding in the switch area are analyzed.The comparative analysis was carried out,and the dynamic response characteristics of the train crossing the turnout under different suspension system parameters were explored.The main contents are as follows:（1）Combined with the existing research work related to the dynamic test of the fork area,the test design was carried out from the aspects of the test purpose,test principle,measuring point arrangement,etc.,the target line test plan was formulated,and the passenger and freight trains before and after the rail grinding in the fork area were successfully carried out.The dynamic test work of the straight crossing switch has completed the data collection of the wheel-rail force and vibration acceleration of the position of the tip rail in the switch area,the guide curve part and the position of the center rail in the frog area.（2）According to the test statistics of the main structural parameters of the vehicle type and the measured rail profile data of the turnout,combined with the dynamic modeling simplification principle,nonlinear processing and linear interpolation methods,two types of vehicle-turnouts,HXD₃ and HXD₁ electric locomotives,were established.Finally,the reliability of the dynamic model is verified by combining with the experimental data.（3）From the three aspects of wheel-rail force,vibration acceleration and vehicle operation safety,the dynamic performance analysis of the train before and after the rail grinding in the fork area is carried out,and the following conclusions are drawn:under different working conditions,the indicators of the train’s vertical fork crossing all meet the safety limit.Both types of trains produce extreme values of wheel-rail force and vibration acceleration near the position of the point rail in the switch area and the center rail in the frog area,and under the same conditions,the wheel-rail force and vibration acceleration amplitude of freight trains are greater than Passenger trains;before the rail grinding in the fork area,the vertical force of the wheel and rail of the passenger and freight trains is concentrated in the 75（25）95k N range,and the lateral force of the wheel and rail is concentrated in the 0（25）15k N range.After grinding,the vertical force and lateral force of the wheel and rail are reduced by 0.77（25）14%and 0.66（25）9.15%respectively;The wheel-rail force,vibration acceleration and derailment coefficient of the train are reduced to varying degrees after the rail grinding in the fork area,indicating that the rail grinding can effectively improve the dynamic performance of the train when it passes the fork.（4）The verified dynamic model is used to simulate the influencing factors of the train crossing dynamics.The dynamic performance of the train crossing is compared and analyzed from the two aspects of track parameters and vehicle parameters.The main conclusions include:about 97%of the wheel-rail contact points Distributed in-6.5（25）50mm intervals,the change of rail profile and gauge in the fork area has an impact on the wheel-rail contact geometric relationship when the train passes;rail grinding and appropriate increase of the gauge can improve the wheel-rail contact geometric relationship,and the proportion of contact points near the wheel flange boundary The distribution of contact points in the range of-5（25）40mm is more uniform;the lateral and vertical stiffness of the primary train springs and the joint stiffness of the secondary lateral shock absorbers have an effect on the lateral stability,derailment coefficient and stability indicators of the train when it crosses the fork.The impact on academic performance is more significant.