Study On Damper And Its Application In Structural Vibration-Reduction Control

Vibration control has become an effective solution to reduce the response of structures in earthquake. One of these methods, passive control using base isolation technique or dampers, has been applied to more and more projects in the past, because they can reduce the seismic response effectively and economically.In this paper, mechanical properties and advantages of several dampers are studied to adopt the appropriate damping device in different conditions. The paper deduced the motion equations of structure system and calculated hypo-optimal stiffness and damping coefficient for control devices with equivalent optimal control method through studying on dampers set on the gallery of adjacent buildings and combined isolation system which formed by dampers set on the gallery and rubber bearings set on the foundation of adjacent buildings.In this paper, we established three systems of 3-D framework models for structures with ANSYS: the adjacent buildings in Free State, dampers set on the gallery of adjacent buildings, dampers set on the gallery and rubber bearings set on the foundation of adjacent buildings. Then we input Qian'an wave and El-Centro wave that simulate rare earthquake of 8 degree (PGA = 400gal) and input Tianjin wave that simulate rare earthquake of 7 degree (PGA = 220gal) to hold simulation analysis for anti seismic effect when the adjacent buildings are in different control systems.The results show that the method which dampers set on the gallery of the adjacent buildings can reduce the structure's earthquake response effectively. When input Qian'an wave and El-Centro wave, the structure's response of adjacent buildings under the control system of the upper damper and base isolation system was evidently reduced, especially the structure's story drift which could be reduced 60%～70%, and the upper structure showed rigid evidently. However, when input Tianjin wave, combined isolation system can reduce acceleration of the structure effectively but maximum displacement of it was increased greatly. The rubber bearings are not fit for the structures which were built on the soft-soil foundation.The research results indict that added dampers structures and base seismic isolated structures can improve the dynamic character of structures obviously and minish the earthquake response of structures. The base seismic isolated structures have advantage in used in multilayer and common high buildings which build on hardpan and half-stiff clay. But for the higher or build on soft-soil foundation buildings added dampers on it is the better choice with thinking over shake by wind.