Research On Vibration Of Railway Beam Bridge Under The Action Of High Speed Train And FVD Vibration Control

Vehicle-bridge coupling vibration is the focus of bridge vibration research,and many scholars have been constantly updated and improved.In this paper,the vehicle-bridge coupling vibration on railway girder bridge and the liquid viscous damper for bridge vibration control are discussed in detail.1.In order to consider the characteristics of high-speed train,slab ballastless track and bridge interaction,the train is simulated as a mass-spring-damped multi-rigid body constrained system,and the motion equation of the car-rail-bridge coupling system is established.In this chapter,the coupling motion equation of the system is established,aiming at the influence parameters of the coupled system,the train's driving state(speed and acceleration),the train's suspension system(stiffness and damping),the rail-rail plate-bridge connection stiffness and damping on the dynamic response of trains,tracks and bridges are analyzed.As well as the vibration response of the coupled system structure when the two-line train passes through the bridge under different conditions.The results show: the change of the train suspension parameters has a great influence on the train's own structure,but has little effect on the rail and bridge structure;The change of acceleration and speed of the train has different degrees of influence on the coupled system.With the increase of train speed and acceleration,the displacement vibration response of the car body own structure is gradually reduced,but the displacement vibration response of the rail and bridge structure is gradually increased;Under different working conditions considered in this chapter,the vibration displacement response of train is more affected than that of rail and bridge,and the peak vibration acceleration of rail is more affected than that of train and bridge.2.Track irregularity is one of the main incentive factors for the coupling vibration of the train-track-bridge,which directly affects the stability and comfort of high-speed train operation.Therefore,studying the track irregularity on the coupled vibration response of the train-trackbridge has become the top priority.Through the characteristics of the interaction between highspeed trains,tracks and bridges,the train is simulated as a system of two-series mass-springdamped multi-rigid systems,and the track and bridge structures are simplified to EulerBernoulli beams.The US six-level orbital spectrum,the German high and low interference orbit spectrum and the Chinese trunk orbit spectrum are used to simulate the orbital random Gaussian irregularity,and then the non-Gaussian random process is generated by the non-memory nonlinear translation process to obtain the orbital random non-Gaussian irregularity,and this acts as a stimulus to the train-track-bridge coupling system.The effects of orbital Gaussian and non-Gaussian irregularities simulated by these four orbital spectra on the dynamic performance of trains,tracks and bridges are compared and analyzed.The results show that: the simulated non-Gaussian correlation function and the target correlation function,the simulated nonGaussian orbital power spectrum and the target power spectrum are all in good agreement,the amplitude of the orbital irregularity in China is smaller than that of the other three orbital spectra,and the second-order orbital irregularity amplitude in china is larger than the other three orbital spectra;Under the four kinds of Gaussian orbital irregularity excitation,the vertical vibration acceleration response of the car body appears to be disordered;The vibration acceleration response of the coupling structure under the non-Gaussian irregularity of the US six-level orbit and the German high-low interference orbit is greater than the Gaussian orbital irregularity,but the Chinese trunk track is not smooth to the rails and bridges,the vibration acceleration response has the opposite effect.3.In this chapter,the bridge is taken as the research object,and the vibration response and vibration control of the bridge are studied.Therefore,when considering the calculation efficiency,the train model is simplified into a series of fixed wheelbase moving loads according to the specific wheelbase and axle weight of the train.A simplified model of the Harmony EMU CRH380 AL,the Shinkansen 700,and the European high-speed train HSLMA8 train was established.The liquid viscous damper is used as the vibration control external device,and the liquid viscous damper is simulated as a finite element damper unit.The existing high-speed railway two-span continuous beam bridge is simulated by multi-degree-of-freedom Euler Bernoulli beam element.Finally,the direct integral method is used to solve the equation of motion of the continuous beam bridge under the action of high-speed train.The influence of train speed and damping coefficient of liquid viscous damper on vibration reduction effect of high-speed railway continuous girder bridge under different types of high-speed train is analyzed.The influencing factors of bridge structure resonance response under high-speed train and the vibration reduction effect of liquid viscous damper installation position on bridge structure vibration response are studied and analyzed.The numerical results show that: Under the same viscous damper condition,the maximum acceleration of the bridge does not increase monotonously with the increase of train speed,but the maximum acceleration of the bridge appears at some specific train speeds,and with the damping coefficient of the damper increases,and the maximum acceleration amplitude reduction at the peak of the vibration response of the bridge is not the same;By reasonably and effectively arranging the train load wheelbase,the train speed of the bridge structure with fundamental frequency resonance can be outside the operating speed,avoiding the large vibration peak response of the bridge structure,that is,the fundamental frequency resonance of the bridge structure;As the connection point between the viscous damper and the main beam is gradually away from the support,the vibration reduction effect of the viscous damper is more obvious;as the connection point of the viscous damper and the abutment is gradually closer to the support,the vibration reduction effect of the viscous damper is slightly improved,but it is not obvious.