A New High-Speed Train Coupled Dynamic System Efficient Modeling Method And Its Application

High-speed railway plays an important role in the transportation field.It also benefits the development of economy in China.Since the demand for rapid transportation between China’s economically developed areas and “One Belt One Road” countries quickly increases nowadays,it is necessary to further increase the operation speed of the high-speed train in China high-speed railway system.However,the increasing of the high-speed train operation speed also means that the vehicle interacts with the track in a large area space over a long period,and it is necessary to model the long track when investigating the high-speed train-track interaction dynamics.At this time,the finite element method(FEM)and modal superposition method(MSM)need to model the whole long track,which results in too many degrees of freedom(DOFs)of the whole train-track interaction model.Thus,their corresponding calculation efficiency is decreased.Therefore,based on the basic theory of the sliding window method,this thesis formulates a new method to investigate the high-speed train-track and pantograph-catenary interaction dynamics accurately and efficiently.This new method names reduced beam model(RBM).The RBM is used to model the high-speed train-track and track-train-pantograph-catenary interaction system,and the dynamic characteristics of the high-speed train under the influence of different track failures are investigated.The main research contents of this thesis are shown as follows:Firstly,based on the theory of the sliding window method,the train-track interaction system is considered as a time-varying system,and the arbitrary Lagrange-Eulerian method is further used here to describe the motion of the main vibration track.The reduced beam theory is then developed.After the formulation of the RBM,it is validated by the FEM through the commercial software ANSYS.Then the RBM is used to model the top speed 400km/h high-speed train-track interaction system.The present train-track interaction model is formulated in commercial software MATLAB,and it is validated by the traditional MSM model.The validation results show that the high-speed train-track interaction model developed by RBM can calculate the dynamic responses of the train-track interaction accurately and efficiently,and its calculation time is only one-third of that of the traditional MSM model.Besides,since the length of the track model in the RBM-based train-track interaction model does not change with the increasing of the train operation distance,the RBM can be used to model a train-track interaction system with arbitrary long track.After the formulation of the top speed 400 km/h train-track interaction model,the track buckling,fastening failure,and track settlement are chosen here and modeled to investigate the influence of track failure on high-speed train dynamic characteristics.When modeling the track buckling,the real shape of the deformed rail in the track buckling area is considered and modeled using the curved beam theory.Thus,the present track buckling model can better present its influence on high-speed train dynamic characteristics.The research results show that a track buckling with its amplitude larger than 70 mm,a fastening failure number larger than 21,and a track settlement with its wavelength smaller than 10 m and amplitude larger than 25 mm threaten the operation safety of the high-speed train.Thus,these kinds of failures must be prevented.Finally,the RBM is further used to model the top speed 400 km/h high-speed train pantograph-catenary interaction model.This model is validated by the contact force test data from the Sweden Regina train.Then the pantograph-catenary interaction model is connected with the above train-track interaction model to formulate a track-train-pantograph-catenary interaction model.Based on this track-train-pantograph-catenary interaction model,the influence of different track failure on pantograph-catenary interaction dynamics is investigated here.The investigation results show that the pantograph-catenary interaction model developed by RBM can also calculate the dynamic responses of pantograph-catenary interaction accurately and efficiently.Besides,while the track buckling and fastening failure have little influence on pantograph-catenary interaction dynamics,the track settlement has an obvious influence on the same.To ensure the current quality,the wavelength and amplitude of the track settlement should also be no more than 40 m and 40 mm.