Study On Traction And Brake System Dynamics Of Heavy Haul Train

Heavy haul transportation is another mark of railway modernization in addition to high-speed train. The development of railway heavy haul transportation have been paid more attention by more and more countries, and been internationally recognized as the direction of the rail freight. In 1980s, Datong-Qinhuangdao railway the first electrified heavy haul rail of China has been built, then, heavy haul transportation has developed rapidly.However, with the increase of train marshalling and hauling weight, and also a longer in length, and more heavy of axle load, and higher speed, the traction force and braking force of heavy haul train is increased, and the propagation time of brake wave is longer, various accidents related to traction and braking characteristics occuered, have seriously affected the safty of the heavy haul trains. Therefore, take a systematic comprehensive study of the dynamic performance on traction and braking of heavy haul train, has a great significance for ensuring safety of the heavy haul train transportation system.Additionly, the current dynamics study of traction and brake are concentrated on the longitudinal dynamics, and have no research on its vertical and lateral dynamics, so, it is necessary to start the study of traction and braking system dynamics which including the vertical, horizontal and vertical dynamics, and this is just the purpose of this paper. What's more, the commonly velocity spread air brake characteristics was widely used in current train dynamic simulation, without considering the dynamic braking characteristics of the air brake, which will result in large errors.Then, according to the limitation of traditional research on dynamics of train, and the errors caused by the commonly velocity spread air braking characteristics, a new method named Modular Modeling Method Based on Circular-Variable and combined with the air brake train simulation system based on the air flow theory have been used in this thesis to make a systematic study on traction and brake dynamics of heavy haul train. The detailed aspects are as follows:(1) The basic principles of traction and braking effect on dynamics of heavy haul train;(2) The dynamic performance while heavy haul train traction and braking on straight lines, curves and ramps railway road condition; (3) Comparative and analysis the longitudinal impulse difference between different locomotive marshalling combinations when traction and braking, to determine the best locomotive marshalling;(4) Comparative and analysis the dynamic performance while empty vehicle marshalling in different location of the train while traction and braking operating condition, to determine the best marshalling positions for empty vehicles.Though the comprehensive analysis of traction and braking system dynamics of heavy haul train, it is easy for us to know the relationship between train dynamics and railway line, formation and operation of train. Furthermore, the analysis results show the dynamic behavior of heavy haul train.