Study On Vibration Control For Bridges With MR-TMD And Dynamic Detection Of Bridges

With the development of high-performance construction material and the wide use of advanced technology of construction, large-span and lightweight structure has become a trend of bridge development, followed by bridge vibration problems increasingly prominent. For the railway bridge, the increased axle loads and train speed will enlarge the vibration of bridge and also intensify the dynamic response of the track and bridges, and then the safety and stationary of train travel has been affected. Therefore it is necessary to study the bridge vibration control. In addition, detecting the health status of bridges in service has far-reaching value.This paper put forward and designed a smart vibration device, which named Magneto-Rheological Tuned Mass Damper (MR-TMD). Based on MR-TMD's control mechanism, vibration control for bridges has been studied. By means of bridge model experiment, the bridge dynamic testing techniques has been further studied. Main content as follow:(1) The danger of bridge vibration, structural vibration control methods, research directions and development trends were reviewed. Existing damping device, control method and engineering application were described. In addition, the research methods of damage detection of bridge are introduced at home and abroad.(2) The parametric model of damper system was built, and the intelligent control method of MR-TMD was studied. Selection of the TMD optimum parameters was discussed, from which can obtain the optimum parameters. The weight matrix selection, control strategy simulation and calculation of semi-active control of the parametric model of MR damper have been studied.(3) The train-bridge-MR-TMD coupling system was established. The coupling system includes train subsystem, bridge subsystem and damper subsystem. Supposed the train under uniform speed, three subsystems were coupled connected by displacement coordination condition and mechanical equilibrium condition. The model of vehicle has 31 DOFs, and bridge subsystem was built by using beam and truss finite element model. Structural parameters of damper subsystem were determined by experimental data fitting and parameters optimization theory. The coupling system was solved by Newmark-βmethod. (4) The examples of German ICE3 train through simply supported beam bridge and a continuous beam bridge was simulated respectively. The vibration effects of bridge were compared under without control condition, installation of TMD and installation of MR-TMD. The damping property of MR-TMD is superior to that of TMD through the comparison of time domain analysis and frequency domain analysis.(5) Dynamic detection model test of bridge was designed, and the feasibility of damage detection model test of bridge was discussed.