Forced vibration test of a building with semi-active damper system

The authors developed a semi-active hydraulic damper (SHD) and installed it in an actual building in 1998. This was the first application of a semi-ac tive structural control system that can control a building's response in st large earthquake by continuously changing the device's damping coefficient . A forced vibration test was carried out by an exciter with a maximum forc e of 100 kN to investigate the building's vibration characteristics and to determine the system's performance. As a result, the primary resonance freq uency and the damping ratio of a building that the SHDs were not jointed to , decreased as the exciting force increased due to the influence of non-lin ear members such as PC curtain walls. The equivalent damping ratio was esti mated by approximating the resonance curves using the steady-state response of the SDOF bilinear hysteretic system. After the eight SHDs were jointed to the building, the system's performance was identified by a response cont rol test for steady-state vibration. The elements that composed the semi-ac tive damper system demonstrated the specified performance and the whole sys tem operated well. Copyright (C) 2000 John Wiley & Sons, Ltd.