Research On Vibration And Control Of Coupling System Of Bridge And High-speed Train

As the speed of train increases,the vibration and control of railway bridge under moving load of high-speed train is particularly important for railway bridge design and health monitoring.The complex dynamic equations of train-bridge coupling system is established by finite element method and Litz method.Dynamic model of train is established according to CRH2 model running on actual railway line,there are 27 degrees of freedom and four axles in this model.The bridge is discretized into spatial beam element and orthotropic rectangular plate element by finite element method.A four span continuous orthotropic plate model is used in the Litz method.The vibration and control of train-bridge coupling system are investigated.Details are as following:(1)Dynamic equations of train-track-bridge coupling system are established by finite element method.Equations of motion are solved numerically by Newmark’s method.Irregularity of track is considered as the internal displacement excitation actting on the trainbridge coupling system.Random displacements along the rail are given by the power spectrum of irregularity.The effects of track irregularity,train speed,vertical stiffness of bridge support,number of train formation and train running acceleration on the dynamic response of trainbridge coupling system are investigated.(2)Dynamic equations of orthotropic plate subjected to CRH2 train are derived by finite element method.Modes of single span orthotropic plates are analyzed by finite element method.Parameters study including moving speed,moving position,irregularity are carried out.Finite element method is used to analyze the modes of multi-span orthotropic plate.Effects of moving speed on the train-bridge system are researched in the case of single-track railway train.Influences of distance of trains entering the bridge on the train-bridge coupling system are researched under the double-track railway trains.(3)Dynamic equations of a simply beam subjected to high-speed train are established by finite element method,dynamic vibration absorbers are installed on the beam.The relationship between the maximum vertical displacement of bridge mid span section and train speed is discussed.The moving speed of the train when the designed dynamic vibration absorber has control effect is determined.The vertical displacement and vertical acceleration responses of bridge and train without dynamic vibration absorber and with dynamic vibration absorber are compared.Dynamic equations of single span orthotropic plate with dynamic vibration absorber subjected to high-speed train are established,and three dynamic vibration absorbers are designed.The influence of train speed on vibration reduction effect is studied.The train speed corresponding to the function of the designed dynamic vibration absorber is determined,and the dynamic impact coefficients of mid span and edge observation points of the bridge without dynamic vibration absorber and with dynamic vibration absorber are compared.(4)Dynamic equations of train coupling with four-span continuous orthotropic plate are established by Litz method.Equations of motion are solved by Runge Kutta method.The natural frequencies and modes of four span continuous orthotropic plates are solved by Litz method and finite element method.Based on the linear control theory LQR,the problem of bridge vibration control is studied by using the HMD method combining passive control and active control.