Performance Of A Novel Damped Redundant Outrigger System Based On Eddy Current Dampers

With the rapid development of the times, more and more tall building arise in the city, in the same time, the anti-seismic property and safety of the structure also have been under the spotlight. Structure with outriggers become the most common structure form of high-rise structure because of which can together the around frame column and core tube and Increase the structural lateral stiffness. However, outriggers always bring about some new problems,such as stiffness or internal force saltation. Also this structure form resist wind and earthquake by Its structure entirely. Designing reasonablely an energy dissipation device to achieve a predictable performance and not to impact the function as well has become a research topic home and broad. The energy dissipation system of super high-rise buildings, in which dampers are equipped vertically between the outrigger and perimeter columns to make full use of motion discrepancy of these two components,get a good effect and had been successfully applied into actual engineering. Considering the needs of the earthquake resistant structure, this thesis put forward a novel damped redundant outrigger system based on the above, in which the necessary outriggers are kept for seismic resistance while redundant outriggers are designed as damped outriggers. In order to the popularization of this new system, make further research, further theoretical and experimental research is needed.Therefore, this thesis organizes the research and conclusion as follows:(1)Based on the simplified model of a real high-rise structure, three different scheme structures are designed in this thesis: fixed outriggers,general damped outriggers and novel damped redundant outrigger system, then the displacement,velocity and acceleration are compared after the analysis; Also, energy method is employed to analyze the energy response of four proposed outrigger system. The results show that the novel damped redundantoutrigger system can get a good damping effect with fewer dampers compare with general damped outriggers system.(2)This thesis summarized the latest research achievements of the eddy current damper,then improved and exploited a reduced scale eddy current damper which the damping coefficient vary between 30~45KN according to the shaking table test needs; Then experimental research on viscous damper and eddy current damper which used in shaking table test are proceed, through which we can understand the performance difference of different damper and povide support for the structure shaking table test.(3)Take simulated earthquake shaking table test on typical structure model with two outriggers, in which different positions and types of the dampers as variables; Response of the structure under different intensity earthquake are calculated, also, some dynamic response index are compared between different schemes. The results show that the novel damped redundant outrigger system can significantly improve the seismic performance of the structure and eddy current damper is a promising new damper.(4)3D finite element models of the test model have been developed in SAP2000, which input same seismic records as the shaking table test. Compared calculation and analysis results with test results, the conclusion can verify the accuracy and reliability of shaking talbe test, but very few inevitable random error.(5)A real super high-rise project has been used as an example, three seismic control schemes are designed, one is a novel damped redundant outrigger system and the other two are the traditional scheme with chevron brace and toggle-brace dampers. The conclusion further demonstrates the availability of novel damped redundant outrigger system after comparative analysis on seismic response and damping effect. Also some optimization design of this engineering is done according to the related theory, including the optimal relationship between the damping coefficient, the axial rigidity of frame column and core bending stiffness. all these working provide the reference to practical engineering optimization design.