| Compared with the traditional bogies,the gauge-changing bogies add a track-changing device and change the matching method of wheels and axles.By adapting the ground-tracking mechanism,the inner distance of the wheelset can be adjusted,which can meet the requirements of different gauge running Claim.As a new type of bogie,the structure of variable gauge bogies is relatively complicated,and the running speed must also meet the current high-speed requirements,so the dynamic performance is more complicated.At present,the research on the dynamic performance of variable gauge bogies in China mainly focuses on the dynamic performance of wide-gauge and standard-gauge operation respectively,and there are few studies on the process of track change.Therefore,it is of great significance to study the track changing process of the gauge changing bogies.This paper combines the relevant industry standards and the structural characteristics of the variable gauge bogie itself,and uses the finite element space beam method to establish a refined model of the frame,and then combines the dynamic models of other main components to achieve the overall structure of the vehicle track system.Combined with the refined model,the Fortran language is used for programming to study the dynamic performance.The main work carried out in this article is as follows:In this paper,according to the method in the finite element theory,the overall stiffness matrix and overall mass matrix in the overall coordinate system of a three-dimensional beam including shear deformation are theoretically obtained.According to this method,MATLAB programming can be used to realize the transformation of the frame structure to the space rigid frame structure composed of space beams,and further to obtain the inherent eigenvalues and eigenvectors of the converted structure.Through solving,we can compare the natural frequency of the structure and the mode shape of the modal analysis obtained by this method and the finite element simulation.It can be obtained that the method in this paper is reasonable to realize the numerical simulation of the framework.This paper introduces and analyzes in detail the structure of the gauge-changing bogie of the high-speed EMU and the structure and principle of the track-changing device on the ground.Based on the Euler-Beamoul beam model,the frame is elasticized,and combined with Professor Zhai Wanming's vehicle-track coupling dynamic model theory,the wheel-rail contact model in the process of variable gauge is established,and the vehicle-track of the variable gauge vehicle is realized.The rigid-elastic coupling dynamic model was established,and the vehicle-track dynamic model of frame elasticity and rigid mode was established with the help of Fortran language.Based on UIC-518 and "200km/h and above speed class EMU dynamic performance test identification method and evaluation standard",the two vehicle models based on rigid frame and elastic frame are compared on a straight line running on 1435 mm standard gauge line Differences in stability,stability,safety and other indicators,combined with the results of data analysis,study the factors that cause differences in dynamic performance.Through the simulation results,it can be obtained that the variable gauge vehicle model established in this paper has better performance in wide-gauge operation.Based on the dynamic model of the elastic frame and the rigid frame,the load change of the wheelset system during the gauge change process,the bending moment of the axle and the vibration characteristics of the frame during the process are analyzed. |
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