Study Of Seismic Vibration Control For A Large Opening Grid Structure With Viscous Damper

The construction vibration control is one of the hot problems within the seismic fortification techniques now.The viscous damper and the application of it in the large openging grid structure,are part of the study about the application of the dissipate energy and reduce seismic responses techniques.The viscous damper is a kind of representative passivity control devices.It reduces the seismic responses of structure by adding the damping and dissipating the vibration energy of the structure .Because this device is simply and the components are cheap, it has a broad application foregroud. However, it is few that study on vibration control method applyes for long-span space truss structures .This paper reviews the interrelated theory about the vibration control and the present state of viscous damper. Meanwhile, the significance and contents of this paper are introduced.Something about viscous damper is researched,such as, consideration of construction, calculation model. And ,working behavior of viscous dampers is nonlinear characteristic. So dynamic analysis for space truss structure with viscous damper is partial nonlinear problem. The paper uses Fast Nonlinear Analysis to solve problems which is suitable for local nonlinear problems. The method is mentioned above is more effective and pricise.In order to study seismic vibration control for a large opening grid structure with viscous dampers,SAP2000 software in finite element method is used to establish the analysis model and to make mode analysis.According to its period and formation , the dynamic characteristics of the structure are mastered, then viscous dampers could be setted up. By inputting Taft three-wave, different dynamic response of the structure between pre and post using viscous dampers is compared .Through observation and study on the axial force of control member and the vertical displancement of control joint,reasonable setting manner is selected. By considering different damping coefficient and number of viscous damper, analysis of damping effect is carried out in the paper . The result indicates that the damping coefficient and number of damper have optimal values. According to standards, another two waves are inputted to do time history analysis and to compare the time history curve of control member and joint .Then, damping effect of the structure is studied by inputting diffent spectrum characteristics seismic wave.It is proved by numerical results that optimal location of viscous dampers is in the middle of every layer ,on the basis of controlling its numberand adjusting its parameter. Viscous damper is suitable to the seismic vibration control of space frame structures,furthermore ,its effect is excellent.