Reduction of structural vibrations by multiple-mode liquid dampers

Abstract

Tuned liquid dampers are low cost devices for passive control of structural vibrations. This paper investigates the combined use of liquid dampers which are tuned to different vibration frequencies of a multi-degree-of-freedom structure. A liquid damper model which was verified by experimental means for nonperiodic excitations is adopted. In the numerical study, a suspension bridge subjected to earthquake excitations is considered. The effectiveness in the reduction of horizontal vibration by using multiple-mode dampers is investigated. The results show that it is beneficial to use dampers tuned to several vibration modes of the structure. The effectiveness of the dampers is dependent on the frequency content of the earthquake spectrum and the positions where the dampers are placed. The optimal positions and optimal mass proportions of liquid dampers of different modes are determined. © 1995.