Simulation Research On Dynamic Performances Of A Certain Type Of Railway Vehicles Based On SIMPACK

In recent years, with the continuous increase of the speed about the railway vehicles, the safety, comfort, light-weight of the vehicles have become the main development trends. So the research on the dynamic performances of railway vehicles is becoming more and more important. For the railway vehicles, the interaction of the wheel and track is one of remarkable characteristics about the railway vehicles. therefore, it is necessary to study the interaction of the wheel and rail, and further analyze the dynamic characteristics of the railway vehicle, and research of the safety, comfort, and so on, which can provide guidance for the design, manufacturing and operation of the railway vehicle.The rigid-flexible coupling theory, dynamics equations of the railway vehicle were investigated and analyzed in this thesis. Based on the finite element simulation technology, those springs in the first and second suspension were simulated and their equivalent stiffness value were obtained. On the basis of the function of power spectral density (PSD), numerical simulation is adopted to inversely solve the spectrum of American5-level track, and obtain the data of track irregularities in the time domain, so as to obtain the excitement data of dynamic model of the railway vehicle in the irregular track.The whole dynamics of a type of railway vehicle is modeled using the multi-body dynamics software SIMPACK. The linear and nonlinear critical speed of the railway vehicle is obtained by simulating different speeds through the linear track, whereas the curve passing ability of the railway vehicle is obtained by using different speeds through the different curved railway tracks. The stability index of the railway vehicle was analyzed under different speeds. The finite element modal of the car body of the railway vehicle was obtained with ANSYS, which was inputted into SIMPACK.,and finally the Multi-body System (MBS) dynamic model was built with rigid and flexible coupling. The dynamic performance of a type of railway vehicles can be thus obtained by solving this model. Finally, on the basis of the principle of sky-hook, the dynamic performance of the railway vehicle is studied by using SIMPACK and MATLAB/Simulink.Through the study, the following conclusions can be obtained. Using the finite element method to simulate and determine the equivalent stiffness of the spring suspension is feasible; the linear critical speed of the type of railway vehicle is between250Km/h and300Km/h; the nonlinear critical speed is233Km/h. The safety coefficient is relatively high when the railway vehicle passes through the level I (and level II) track in140Km/h; the stability index is about2.8, which is belong to the optimal level. When the speed of the railway vehicle is100Km/h, the biggest deformation of the flexible car-body is about9.15mm. Compared with the rigid body, the vertical acceleration of the railway vehicle with the flexible body have increased, and amplitude change is tiny. In addition, the vehicle angle acceleration has gotten slightly smaller. The vertical vibration acceleration of the car body has declined obviously under sky-hook damping control technology, and the better ride comfort can be obtained.