On the damping of wind-induced vibration in tall buildings

Abstract

Needless to say that the use of tuned liquid dampers (TLDs) in damping wind-induced vibration is indispensable in controlling the effect of fatigue stresses caused by repeated excitation loads. The serviceability of high-rise buildings and steel towers constitutes another important application of TLDs to suppress building acceleration and achieve comfort and healthy conditions. This paper presents a new numerical model developed to investigate the effect of TLDs on the response of structures subjected to external excitations caused by wind. Earlier numerical algorithms postulate equivalent mechanical models for both the structure and the liquid in the TLD. These models are either based on the potential flow theory or the shallow-water theory. The first theory neglects the effect of fluid viscosity; while the later cannot be used to model fluid sloshing motion around obstacles or violent sloshing waves caused by large amplitude excitations. The current numerical model predicts the effect of TLDs on the structure dynamics by solving the full Navier-Stokes equations for the viscous liquid sloshing motion inside the TLD. The current model handles the moving free surface by using the volume of fluid method and uses the continuum surface force model (CSF) to handle the discontinuity accompanied with wave breaking. The present model incorporates the interaction between the structure dynamics and the damping effect of various TLDs located at different floors of the tall building. The model has been validated by direct comparison with full-scale field measurements taken at the National Bank of China building. The comparison shows that the current model can accurately predict the damping effect of TLDs on structure dynamic response.