Research On The Dynamical Characteristic Of The TVMD And Its Seismic Control Performance For Continuous Beam Bridge

Earthquake prevention and disaster reduction of engineering structure have gained wide attention. Installing dampers in the appropriate location of the engineering structure as the device of energy dissipation, the response of the structure can be effectively reduced by adding structural damping. In this paper, a new type of passive damper - Tuned viscous mass damper (TVMD) was introduced, and its energy dissipation characteristics was studied in detail, and on the basis of continuous beam bridge its damping performance was explored. The main work is as follows:(1) The performance of single damper was analyzed.The output force of TVMD was divided into two parts, the elastic force and the damping force, and then the equivalent stiffness coefficient and the equivalent damping coefficient were obtained, and the relationship between them and the damper parameters was analyzed. Based on the single degree of freedom system, the effects of equivalent stiffness and equivalent damping on seismic isolation were discussed. The displacement and acceleration response spectrum curves of seismic waves with different characteristics were drawn. The efficient damping performance of TVMD on single degree of freedom structure was clarified according to the change of the response spectrum curve before and after the installation of TVMD.(2) A simplified method of regular continuous beam bridge is established, which is a simplified analysis model of two degrees of freedom. Based on this model, the damping performance of TVMD was discussed. The influence law of the damper parameters on the dynamic magnification factor of the target response was analyzed, and then summed up the optimal parameters. The control effect of TVMD on the damage caused by the failure of the bridge bearing under strong earthquake are discussed. The three-span continuous girder bridge was simplified as a multi degree of freedom model, and the optimization design of TVMDs in the transverse and longitudinal direction was carried out. Using H2 optimization method to optimize the TVMD parameters, and compared with the common viscous damper (VD), the results show that TVMD has better shock absorption effect than VD.(3) By means of the Highway Bridge Benchmark problem the damping performance of TVMD was investigated. Firstly, the dynamic analysis of the bridge structure was carried out, and then the mode which need to be reduced was determined. Multiple TVMD were installed at the same time in the transverse and longitudinal direction, and the parameters were optimized. Multiple evaluation indexes were selected to investigate the effect of TVMD under multiple bidirectional seismic wave. The results show that, except that the acceleration control effect is slightly insufficient, evaluation indicators such as displacement and pier bottom shear force are all reduced in various degree. Compared with VD, TVMD is more efficient for the vibration reduction of bridge structure.