The Simulation And Longitudinal Dynamic Analysis Of Mixed Formation Freight Train

With the development of China’s national economy and the optimization of industrial structure,the demands of the transportation on coal,steel and other traditional bulk cargo were relatively reduced.The demands of the transportation on diversification,high value-added features such as the rapid growth of cargo were relatively increased.In order to meet the needs of today’s domestic transportation of goods and enhance the competitiveness of rail transportation to improve the economic benefits.The fast freight train of 160km/h should be promoted as soon as possible.The development of fast railway transportation not only has important practical significance,but also meets the trend of world rail transport.The speed of the rapid freight car is up to 160km/h.With the increase of the running speed of the train,the longitudinal impulse of the train is obviously exacerbated.The result is the shortening of the service life of the vehicle parts,the breakage of the coupler,the damage of the vehicle body and the cargo,seriously affecting transport safety.In order to further improve the efficiency of railway transportation,it is necessary to consider the combination of fast trucks and ordinary trucks for cargo transportation and return.There are differences in braking characteristics between the rapid freight car and the general freight car.During the mixed train braking emergency,different types of cars spend different time to fill brake cylinders.This difference in time may increase the synchronism of braking effect between vehicles.This synchronism may cause the acceleration and the longitudinal impact of the train increasing,which will affect steady running of the train and endanger the transportation safety of goods.In this paper,we use the air brake system and longitudinal dynamics of train combined simulation system to calculate and analyze the longitudinal impact of mixed formation train.Combine with the braking process of the train’s vibration state of the law of the causes of numerical analysis.Making a brief introduction of the influence of the initial braking speed and the inflating speed of the fast truck brake cylinder on the longitudinal impulse of the mixed formation train.The result show that,the train that rapid cars placed at the front and rear position cause greater coupler force between cars.The rapid cars should be marshaled in the middle of the train as possible.The uneven distribution of train braking force is an important factor to influence the train longitudinal impulse.The maximum longitudinal force performed pressure coupler force when the cars with stronger braking force placed in the front and middle position.When the rapid cars placed at the rear position of the train,the maximum longitudinal force performed pulling coupler force.Under the mixed position train of both rapid and general cars,the connected location occurred the great longitudinal impact between vehicles.