Research On Dynamic Performance Of Multimodal Transportation Freight Suspended Monorail Vehicle

Nowadays,China lacks cooperation and effective connection in railway,highway,water transportation and civil aviation transportation.As an efficient way of transportation organization,multimodal transport plays an important role in reducing the cost of social logistics and improving the transportation efficiency of goods.Under the background of the national development of container multimodal transport,the mode of transportation needs to be broken and innovated.Suspended monorail system which was mainly used for sightseeing and tourism has been used for more than one hundred years in foreign countries.It has the advantages of low cost,excellent climbing ability and strong adaptability.However,it is the first time to apply the suspended monorail system to container multimodal transport.It's dynamic performance is also urgently needed for further study.Based on the analysis of the other transport vehicle dynamic performance index at home and abroad,the dynamic performance evaluation criterion for freight car is proposed,which is combined with the structure and operation characteristics of the truck bogie.It mainly includes the performance indexes of vehicle operation quality and operation safety.Rubber tires are used in multimodal transport suspended freight monorails.Considering that the semi-empirical tire model has high simulation accuracy and wide application features,MATLAB/Simulink software is used to simulate the Pacejka tire model to obtain tire dynamic simulation characteristic curve.The relationship between longitudinal force and longitudinal sliding rate,lateral force and lateral angle,the aligning torque and the lateral angle are discussed.According to the structure characteristics of the bogie,the transfer process of each force and the motion differential equation of motion are determined.The dynamic simulation model of vehicle system was established by using SIMPACK software.And it's dynamic performance was simulated and evaluated on this basis.The results show that the vehicle can achieve good riding stability,riding quality and curving performance.The influence of the lateral clearance between guide wheel and rail beam,the main suspension parameters of bogie and crosswind on the dynamic performance were analyzed.The simulation results come to conclusion that the lateral clearance between guide wheel and rail beam mainly affects the guiding force and lateral stability of the vehicle through the curve.Considering assembly error and rubber wear,it is recommended to take 2mm clearance between guide wheel and rail beam.The transverse hydraulic shock absorber can be installed to effectively reduce the roll angle of the vehicle body.However,the damping larger value increases the lateral vibration acceleration of the vehicle body.It is suggested that the damping value of each transverse hydraulic shock absorber is 90kN·s/m.The crosswind mainly affects the horizontal stability,the wheel unloading rate,the overturning coefficient,and the roll angle of the vehicle body.According to the simulation results,the vehicle should be stopped running when the wind speed reaches level 8.In addition,the operating speed of the vehicle under the wind at level 7 should be limited to under 30km/h.The dynamic performance of the suspended freight car is systemic analyzed,and the dynamic performance evaluation criterion for freight car is proposed.In addition,the suspended parameters of bogie are optimized,and its dynamic performance is predicted and evaluated.The research results are of great significance to promote the development of multimodal transport in China.