Study On Aseismic Performance For Energy Dissipation Braced Structures With Viscous Dampers

Due to absorbing excessive earthquake energy, some members in traditional structures may enter into elastic-plastic state, even yield or fail under strong earthquake, with a consequence of repair failure later or direct collapse. Dampers added to structures are responsible for consuming energy introduced by earthquake or other dynamic inputs. The supplemental energy dissipation systems can be used to control story drift, improve or upgrade the structural aseismatic performance of new or existing building. This technique has been becoming one of the main tendency of earthquake-resistant engineering research. Scholars and engineers in this area in many countries are being engaged in this field of research and practice. A direct numerical integration of the equations of motion is a general method for analyzing damper-added structures. The motion equations of damper-added structures and the dynamic time-history analysis procedure are discussed in detail. The procedure can solve a SDOF system, a MDOF system, a system considering torsional responses, or a three-dimensional finite element system. When the structure keeps elastic except for the local nonlinearities, the fast nonlinear analysis (FNA) method is desirable for an elastic response history analysis.And the fast nonlinear analysis (FNA) method in the program SAP2000 that has been expatiated in the thesis. In this paper, the research object is based on a 12-storey reinforced concrete structure. Three structure systems such as frame and the dissipate energy and reduce seismic responses structure installed with viscous damper are used to build up as three-dimensional modals. A finite element method SAP2000 program is used to analyze the modals' intrinsic vibration characteristics. SAP2000 program is also used to analyze the elastic dynamic time history analysis of EL Centro seismic wave and Taft seismic wave at usual level and elastic-plastic dynamic time history analysis at unusual level. It is validated it can reduce the seismic-performance. Meanwhile, the influence on the reducing seismic performance of the structure is compared and analyzed when the damper choose the different brace stiffness and the different speed parameter. It is concluded that the damper with big brace stiffness and small speed parameter pose the more effective energy-dissipation performance. Additional the effect of damper's installing projects on structure force are analyzed. It is indicated different project have the almost same effects. The research results illustrate that the viscous damper is not only can work effectively under usual level seismic but also can do under unusual level seismic.