| China’s urban rail transit system has developed rapidly in recent years,with a total mileage of more than 5000 km.As an important part of urban rail transit system,subway can carry large passenger volume,which is one of the most important choices for urban residents in today’s society.It is also the mainstream system of urban rail transit in China,accounting for the vast majority of the total mileage.Many factors such as the layout and planning of the city,the analysis and prediction of passenger flow,and the reasonable layout of stations and sections need to be considered in the subway route.Many horizontal curves and ramps will inevitably be set in the route selection.The minimum curve radius of the normal subway main line is usually 300 m,while the curve radius of the depot is smaller.According to the basic theory of dynamics,the angle of attack of the steering wheel of the Metro Bogie is directly proportional to the wheelbase and inversely proportional to the radius of the curve.Therefore,the smaller the radius of the curve,the larger the angle of attack of the steering wheel,the sharp increase of the wheel rail wear index,and the increase of the interaction and wear between the wheel set and the track,which is accompanied by a series of dynamic problems.The dynamic performance of metro vehicles is analyzed in this thesis,focusing on the curving performance of metro vehicles,and the influence of vehicle suspension parameters on the curving performance of metro vehicles is also analyzed.First of all,the research of domestic and foreign scholars on the problem of vehicle curve passing is summarized in this thesis,and draws on the existing research results and methods to form the technical route of this thesis.Take a B-type subway vehicle as the object and simplify the part of the vehicle structure to a certain extent.Use multi-body dynamics software to establish a complete vehicle dynamics model,aiming at the main suspension parameters of the vehicle,analyze its influence on the vehicle curve passing performance through the method of control variables.Through analysis and research,we found that choosing a larger longitudinal stiffness of the primary system will limit the relative longitudinal displacement between the wheelset and the frame to a certain extent,so that the wheelset can not rotate well relative to the bogie,and the interaction between the wheel and rail will increase when passing the curve,which is not conducive to the curve passing of vehicles.With the increase of secondary longitudinal/lateral stiffness,the wheel rail lateral force and derailment coefficient increase,but the wheel rail vertical force and wheel load reduction rate decrease.So,secondary longitudinal/lateral stiffness should be selected reasonably.The first series longitudinal stiffness and the second series longitudinal/transverse stiffness are re selected,then the dynamic performance of the vehicle is analyzed.Compared with the original vehicle,it is found that the improved suspension parameters can improve the interaction between wheels and rails,improve the curve passing performance of the vehicle,but the stability and stability have decreased.Other suspension parameters are analyzed in this thesis,which have little influence on vehicle curving performance,focus on their influence on vehicle stability and stability,and reselects these suspension parameters.At the same time,a series of anti-shake shock absorber devices are added.By analyzing the influence of the damping coefficient of a series of antishake shock absorbers on the nonlinear critical speed of the vehicle,a suitable damping coefficient is selected.In the end,the improved vehicle not only improves the curve passing performance of the vehicle,but also takes into account good vehicle stability and smoothness,which shows that the value of each suspension parameter is more reasonable. |
PDF Full Text Request