Suppression of vortex-excited vibration of tall buildings using tuned liquid dampers

The objective of this paper is to study the control effects of rectangular TLDs installed on a tall building that vibrates due to vortex excitation. Optimal design properties of these TLDs and their control performance are first obtained using the characteristic equation of the TLD-building system. Wind tunnel experiments are performed on a scaled-down building model equipped with rectangular TLDs of various sizes. The liquid heights of the TLDs are varied to determine an optimal TLD's frequency range for this building model under vortex-induced vibration. A total of 34 test cases that correspond to different TLD geometries are performed for wind speeds ranging from 1.5 to 4.2 m/s. It is found that the rectangular TLD is quite effective in reducing the vortex-excited vibration of a building, especially when its frequency is tuned to within the optimal range. The top displacement RMS value reduces to only one-sixth of that of the original building model without a TLD when the generalized mass ratio equals to 2.3%. The optimal frequency of the TLD range between 0.9 and 1.0 of that of the building model which is consistent with the analytical derivation. (C) 1999 Elsevier Science Ltd, All rights reserved.