Research On Wheel/Track Interaction Of The Heavy Haul Freight Car

As one of the most important transportation method,railway transportation has many advantages,such as high speed,big volume,safety and low energy consuming, which takes an important part in economy development in the world.From 1960s,many countries realized that developing heavy haul freight car is an effective way to improve railway transportation volume.Thus these countries began to increase axle load of freight car,and take far-ranging research on the wheel/track ineraction worsened by axle load increasing. Several kinds of low track force bogies for heavy haul freight car were designed.Railway always plays guiding role in our transportation system.But inconsistency between rail transportation capacity and needs is quite serious.Thus heavy haul transportation is needed urgently.So Minstry of Railway has decided to develop 25t-axle-load freight car bogie with low wheel/track interaction,in order to increase axle load of freight from 21t to 25t.From "the eighth five-year plan" to "the ninth five-year plan",wheel/track dynamic force of heavy haul freight car is investigated by some domestic researchers,and several kinds of freight car bogies with low wheel/track dynamic force were developed.But tests showed that those bogies were not so effective in reducing dynamic force.As the main 21t-axle-load freight car bogie of new generation, the bogie ZK2 is being popularized in our country at present.The cross-bracing bogie ZK6 with 25t axle load was developed based on the bogie ZK2,and was used in heavy haul trans-portation.Based on the background of heavy haul freight car with higher speed is being developed to realize rapid heavy haul transportation with low standard track force,the thesis analyzes the wheel/track dynamic force worsen by axle load increas-ing.Then some methods to lower dynamic force between heavy haul freight car and track are discussed.It's quite meaningful to develop our heavy haul railway transportation and choose the heavy haul freight car bogie in the future.Firstly,the heavy haul freight car model with three-piece bogies is built, including many nonlinear factors of freight car.Secondly,the influences on wheel/track interaction resulting from axle load increasing of freight car are analyzed based on this model.Finally,several freitht car and track methods to reduce wheel/track dynamic force are gotten. Some advice of freight bogie tecnique improvements and trackmaintenances to lower wheel/track dynamic force is put forward as well.