Application Of Viscous Fluid Damper In Seismic Retrofit Of Frame Structures

Viscous Fluid Damper has been widely used in the anti-wind and anti-seismic design of practical engineering structure, with its good damping effect. The use of energy dissipation method for seismic strengthening of existing buildings is a new trend in recent years, by adding energy dissipation device to the structure, which has been widely concerned.Based on summarizing the abroad and domestic papers about VFD, with the practical engineerings, using the finite element simulation method, this paper has made a comprehensive study on the energy dissipation structure with VFD about the theoretical calculation, Parameter analysis and controling effect. The main research contents of this paper are as follows:1) The paper has introduced a engineering example which is a reinforced framework using VFDs, and a nonlinear calculation model of three-dimensional structure has been established by using SAP2000finite element analysis software. It has studied on the natural vibration characteristic of original structure through modal analysis method,and then it has designed earthquake and chose parameters of VFD.2) Under the frequent earthquakes, the upper structure adopted linear elastic model, and VFDs used nonlinear link element model in the system analysis model. The time history analysis shows that the VFDs have played fine controling role in interstory displacement angle, absolute acceleration of floor and the reaction of base shear.3) Under the rare earthquakes, the beams and columns of the structure used rod end plastic hinge model, and the VFDs used nonlinear link element model in the system analysis model. The paper counted up and analyzed the situations of plastic hinges in every piece of structure framework. The nonlinear time history analysis shows that the VFDs not only effectively reduces elastic-plastic interstory displacement angle and interstory remnant displacement, but also alleviates the rotation demand of beam column plastic hinges, so that it can mitigate the damage degree of the structure in the earthquakes.4) A SAP2000API plug-in for calculating the members’damage index based on Park-Ang damage model has been developed, which effectively improve the efficiency of data processing in complex space model, structural damage index has been calculated by using weighted combination method, which is used to verify the damping control effect by using this kind of damper.