Dynamic Modeling And Coupled Effect Analysis Of High-speed Train-turnout System

Turnout is one of the important parts in railway, and also is the major element to decidetrain’s speed and safety. For a long time, due to train all pass turnout in a low speed, it’s notobvious that coupled between train and turnout, so it doesn’t cause enough value. But withtrain run in a high speed, dynamic effect between train and turnout gets more and moreintense, this need to treat turnout and train as a big system, and research common low to thesystem, to improve vibration condition in the system, enhance train’s pass turnout speed.The article adopts multi-system dynamics software Universal Mechanism (short for UM)as modeling and simulation platform. Its general process of modeling and solving modelinclude geometric modeling, physical model, mathematical models, analyze results. Vehicledynamics model is simplified into seven rigid bodies such as a body, two frameworks, fourwheels are included before modeling. Taking into account transverse degrees of freedom, thevertical degree of freedom, roll degrees of freedom, shake head to degrees of freedom and noddegrees of freedom, switch model is simplified into uniform the Euler beam which can bendbilaterally. Tongue rail and point rail are all the Euler beam which can bend bilaterally. Theclose contact section between switch point and stock rail is regarded as a rail, as well as theclose contact section between point rail and wing rail, they are involved in common vibration.The oscillation equation of vehicle subsystems and switch subsystem as mathematical modelsduring the modeling in the UM.We set up the geometric model of railway, and the section shape of No.18tempted railtype single turnout which is60Kg/m is drew utilizing CAD firstly. The coordinates of railsection are extracted, which is imported into UM, and a smooth track model is generated withinterpolation method. Then we can get the physical model of railway by importing linearmass, moment of inertia and modulus of elasticity. The physical model of vehicle isestablished utilizing the3-D structure modeling function of UM according to the geometricalparameter of body, framework and wheel set. We get the physical model of vehicle byensuring position space of rigid body, and connecting the rigid body with force element, thenimputing mass and moment of inertia of rigid body as well as the stiffness and damping offorce elements. Setting up the vehicles-rail system coupling dynamics model in the UM usingthe mathematical models above. We take wheel-rail force as validation criteria of simulationresult. Comparing the value of rail force with the existing literature, the results are in goodagreement, and it indicates that the coupling dynamics model is correct. At last, takingvehicles-rail system coupling dynamics model as target object, the vehicle passing throughthe turnout in the reverse side350km/h and straight reverse80km/h are simulated with theprocess of calculation of initial conditions, equation set automatically and analysis iterations in the UM. According to the simulation results of the two kinds of working conditions, weanalyze track vibration acceleration and the vibration acceleration, displacements, derailcoefficient of vehicles and their parts.Simulation reveals that: When vehicles run through the turnout in the side direction, inswitch rail area, it will occur instantaneous impulse force that peak higher between wheel andpoint rail, In frog rail area, wheel back will impact guard rail occur instantaneous oppositeforce. When vehicles run through the turnout in the straight direction. shortwave irregularityof rail system has a great influence to the whole system, so vibration parameters of vehiclesystem and rail system in frog area are more larger than them in switch area.