The Influence Of Structrual Flexibility Of Wheelsets On The Simulation Results Of Railway Vehicle’s Performance

The last decades have witnessed a substantial development of high speed trains such as TGV in France, ICE in Germany, Pendolino in Italy, Shinkansen in Japan and X2000in Sweden. And in the last years, the high speed trains in China has also developed a lot, like the CRH series EMUAs the speed of the trains is getting faster and faster, the frequency of the shock that the trains would be taken will be much higher, and the vehicle-track interaction would also be stronger.Then there wolud be some new problems, like the wheel-rail corrugation, wheel-rail noise, wheel out-of-roundness, degradation of the ballast and so on, And those problems were thought to be caused by the vibration in the middle frequency range, so people started to study the influence of vibration in the range50-500Hz on the vehicle-track dynamics.The parts of vehicle would be treated as rigid bodies in the research of the vehicle system dynamics before, but now as the speed of the trains is getting faster, the frequency of excitation would be much higher, and at the same time, the demand of the lightness of the vehicle parts will lower the stiffness of the vehicle parts, so it worths to use the flexible multibody system dynamics to study the vehicle-track system to find out the influence of the structural flexibility of the vehicle parts like wheelsets, bogie frame, car body and the rail on the simulation of the vehicle system.This thesis first makes a simple introduce to the main parts of a high speed trailer car, and then builds the dynamic model by using the multibody system dynamics software SIMPACK. With the application of the common finite element software ABAQUS, the flexible body of wheelset is obtained, then after the process of SIMPACK, we build the rigid-wheelsets vehicle model and flexible-wheel sets vehicle model. Then these two models are simulated, the results of critical speed, the performance on straight line and passing curves are obtained, last the influence of the structural flexibility of wheelsets on the simulation results is analyzed.The nodes are defined in the ABAQUS input file, the finite element model is represented through these nodes, and then the mass matrix stiffness matrix and modal information are output by defining the key words. After the process of FEMBS, the file of flexible wheelsets is obtained, and last the flexible-wheelsets vehicle model is modeled in the SIMPACK.A short part of track excitation is given to the vehicle models, the vehicle critical speed is then obtained by analyzing the history of lateral displacement of wheelsets. The result is that the vehicle critical speed of the flexible-wheel sets vehicle model is lower than the rigid-wheelsets vehicle model’s, but the difference between them is small. Then, we study the performance of the vehicle under the excitation of German high speed track spectrum. After analyzing the simulation results, we find that the performance of the two models on the straight line was quite the same. But to the performance of passing curves, there were some difference between them, for example:the lateral acceleration of the carbody of the flexible-wheelsets vehicle model is a little higher, but the vertical acceleration of the carbody of the rigid-wheelsets vehicle model is a little higher; the wheel-rail lateral force of the flexible-wheelsets vehicle model is bigger than the rigid-wheelsets vehicle model’s; but the reduction rate of wheel load of the two model’s are quite the same.