Study On The Influence Of Anti-kink System On Low-floor Trams Dynamic Performance

With the gradual expansion of urban scale,low floor trams,as a new type of vehicle,have attracted more and more attention from major cities because of its convenient,rapid,low carbon environmental protection and economic characteristics.The low floor tram adopts a variety of vehicle structure forms to improve the performance during curving,and the conventional rolling stock is basically a typical four axle double bogie structure.Because of the change of bogie and car body structure,most low floor trams have more freedom from the structure,so there will be Z shape bending between the car bodies,which lead to the differences between the low floor tram and the traditional urban rolling stock on the small curve negotiation performance.In order to deal with the bending movement of vehicles,the influences of hydraulic anti-kink system on the dynamic performance of trams is studied in this thesis.Firstly,the origin and development of low floor trams,the application status of low floor tramcars at home and abroad as well as different types of low floor tram bogies are introduced in this thesis;the causes and solutions of the bending movement of tram car body are also analyzed;then,the mathematical model of the hydraulic anti-kink system is analyzed,and the AMESim simulation software is used to establish the analysis model of the hydraulic anti-kink system,and the influences of the main parameters of the anti-kink system on the stiffness and damping characteristics of the anti-kink system is studied.In order to better simulate the actual running environment of trams as well as the interaction between the anti-kink system and the vehicle,a vehicle dynamic model based on SIMPACK,a hydraulic anti-kink system model based on AMESim,and a co-simulation platform with Simulink as the medium are established.Based on the co-simulation model established,the impacts of normal mode anti-kink system on vehicle’s straight line performance are analyzed at first in this thesis.Further,two different vehicle models were simulated before installing anti-kink system under different radius tracks and after.In order to further study the effects of anti-kink system on the performance of vehicle during curving,the effects of anti-kink system on vehicle dynamic performance at a high speed when negotiating S curve and C curve are studied.The influences of anti-kink system on vehicle curving capacity are studied comprehensively.Finally,the effects of the anti-kink system on the performance of the vehicle in different modes are analyzed in this thesis.The emergency braking condition and the traction braking failure condition are studied in the failure mode.The working conditions of the pushing vehicle through the ramp are simulated in the rescue mode,and the influences of the anti-kink system on the running performance of the vehicle in a harsh environment are studied.The study shows that the influences of anti-kink system on vehicle dynamic performance are related to the speed of vehicle when running on the straight line.When the vehicle travels on the straight line at different speeds,the anti-kink system can improve the ride comfort of the vehicle,but it will increase the related dynamic index to a certain extent.When the curve passing,especially the S curve and C curve passing,the anti-kink system has a great influence on the safety of vehicles.At the same time,it is indicated that the vehicle equipped with anti-kink system still performs better in fault mode and rescue mode,which can ensure the safety of vehicle.