Seismic response control of steel benchmark building with a tuned mass damper

Abstract

The effectiveness of a tuned mass damper (TMD) in dynamic vibration mitigation of a 20-storey steel benchmark structure (SBB) under real earthquake ground motions is presented. To study the positioning and tuning effect, a TMD is positioned at the largest or relatively larger of the normalized amplitude of mode shape of the selected structure. At each location, a TMD is tuned with different modal frequencies, while mitigating first five modal responses. The response of the SBB equipped with a TMD is obtained by numerically solving the differential equations of motion under different earthquakes, and subsequently compared with the corresponding uncontrolled building (NC), in order to investigate the efficiency of a TMD in seismic response control of buildings. Parameters considered for this study to be varied are (1) placement, (2) tuning frequency, and (3) mass ratio. The changes in the performance criteria (response) under various seismic excitations are calculated to evaluate the effectiveness of a TMD tuned to various modal frequencies, which are placed at different locations. It is noticed that the TMD tuned to the fundamental modal frequency and placed at the topmost floor leads to the best performance under earthquakes. It is also observed that controlling the higher modal response by a TMD will be efficient to substantially mitigate the seismic response of the SBB.