지진하중을 받는 다층 건물에 설치된 마찰감쇠기 설계 = Design of Friction Dampers installed at a Multi-Story Building under Seismic Load

다국어 초록 (Multilingual Abstract)

In this study, a simplified design procedure for friction dampers of a multi-story structure in order to reduce seismic response is proposed. To get insight for control effect of the structure with friction dampers is difficult, because of a nonlinear characteristic by a friction damper. Since a control force of a friction damper is influenced by coupling velocity between floors, adjoining modes are coupled. Thus structural response are derived by assuming steady-state response in resonance. As it is impossible that an exact solution is obtained for seismic load, first, a closed form solution can be achieved under harmonic vibration. Second, to convert a three-story building into a single-degree-of-freedom(SDOF) structure, modal analysis is performed. Third, an equivalent damping ratio is derived with utilizing closed form solution. And response reducing factor is proposed by it. Finally, friction force of a damper is designed for using response reducing factor, and then designed dampers are verified for seven seismic data. The nonlinear analysis results confirm the validity of the proposed procedure.

국문 초록 (Abstract)

본 논문은 지진응답을 제어하기 위해 다층 건물에 설치된 마찰감쇠기의 간단한 설계절차를 제안하였다. 마찰감쇠기는 비선형성이 강하므로 마찰감쇠기가 설치된 건물의 제어효과를 파악하는 것은 어렵다. 마찰감쇠기의 제어력은 층간속도에 영향을 받으므로, 인접한 모드가 서로 연계된다. 따라서 응답은 공진일 때 안정상태응답으로 가정하여 유도하였다. 첫째로 지진하중에 대한 정해응답을 구하는 것은 불가능하므로 조화가진을 받을 때의 근사해를 유도하였다. 둘째, 다층 건물을 단자유도로 변환하기 위해서 모드해석이 수행되었다. 셋째, 근사해를 이용하여 등가감쇠비를 유도하였다. 그리고 등가감쇠비를 이용하여 응답감소계수를 제안하였다. 마지막으로, 마찰감쇠기의 마찰력을 응답감소계수에 의해 설계하고 설계된 감쇠기를 7개의 지진파를 통해 검증하였다. 비선형해석 결과가 제안된 절차의 유효성을 확인하였다.

참고문헌 (Reference)

1 민경원, "단자유도 건물의 지진응답제어를 위한 마찰감쇠기 설계" 한국소음진동공학회 20 (20): 22-28, 2010

2 Min, K.W, "Simple design procedure of a friction damper for reducing seismic responses of a single-story structure" ELSEVIER SCI LTD 32 (32): 3539-3547, 2010

3 Hundal, M.S, "Response of a Base Excited System with Coulomb Viscous Friction" 64 (64): 371-378, 1979

4 Crandall S.H, "Random Vibration" Academic press 165-, 1973

5 Marko J, "Influence of Damping Systems on Building Structures Subject to Seismic Effects" 26 (26): 1939-1956, 2004

6 Liang, J.W, "Identifying Coulomb and Viscous Damping from Free-vibration Acceleration Decrements" 282 : 1208-1220, 2005

7 Den Hartog, J.P, "Forced Vibration with Combined Coulomb and Viscous Friction" 53 : 107-115, 1931

8 Chopra, A.K, "Dynamics of Structures" Prentice Hall 844-, 2001