Study On The Coupling System Dynamics For Three-Piece Bogie Tank Cars Taking Into Account The Liquid Sloshing

The three-piece bogie has been running for about sixty years on the tracks of North America, South Africa, China and other countries. Without doubt, the significant advantages of the bogie are due to the very simple structure, safe and reliable operation, low price and maintenance costs, long service life and low energy consumption. Although some new radial steering bogies have been developed for the freight vehicles and other types used in many counties, the family of three-piece bogie still shares large market in the world. That is not to say this type of railway vehicles has no disadvantages, on the contrary, its lower critical speed on straight track, the high dynamic track loads, the performance relying on the state of wear strongly influence its dynamical performances. Along with the flourish development of railways, the lower speed and wear problems have restricted the development of the three-piece bogie, and this traditional type of bogie has not suited the requirement of increasing railway transportation speed in China.Because of the sloshing of the liquid cargo carried by railway tank car, the conventional multi-body system dynamics methods can't solve the liquid-solid coupling problem entirely. The rapid development of the nonlinear dynamics, liquid-solid coupling system dynamics, computer science and computational mathematics have provided necessary theories and feasibility to study the nonlinear liquid-solid coupling system dynamics of railway tank cars.In this dissertation, with the help of multi-body system dynamics and liquid-solid coupling system dynamics, the mechanical characteristics of sloshing liquid for cylindrical tank in horizontal state is investigated. The mechanic feature of sloshing liquid is analysed, as well as the eigen program of liquid sloshing with a free surface is calculated by means of Hamilton variational principles and Ritz method. According to the strict equivalent principle, the equivalent mass-spring mechanic model is established to study the liquid sloshing problems. At the same time, the result of a simple rectangle tank with a free liquid surface calculated by given method is compared with the accurate analytic solution to verify the validity and veracity of the method given in this dissertation.