APPLICATION OF TUNED LIQUID DAMPERS WITH SCREENS TO CONTROL SEISMIC RESPONSE OF STRUCTURES

The Tuned Liquid Damper (TLD) is nowadays increasingly being used as an economical and effective passive vibration absorber. This research focuses on modeling tall buildings equipped with Tuned Liquid Dampers (TLDs) subjected to strong ground motions. Strong excitation, can cause wave breaking phenomenon and makes turbulent in shallow rectangular tanks which could also contribute to the additional damping due to TLD’s. Wire screens placed inside of the liquid tank can play an important role on reducing the structural response, due to increasing the inherent damping of the structure. In this study a simple method for modeling this type of Tuned Liquid Dampers by using Equivalent Amplitude ependent Tuned Mass Damper is implemented. The method is based on equalizing dissipated energies in both devices. Equations of motion for shear-type buildings equipped with nonlinear Amplitude Dependent Tuned Mass Dampers are developed. A complex modal analysis procedure is used to solve the governing equations. Coupling of TMD properties and structural response is solved with iteration on structural response and updating TMD’s propepties. Performing a set of parametric studies on a practical structure equipped with TLDs subjected to different ground excitations, showed that if the Tuned Liquid Damper is tuned to the natural frequency of structure considering the hardening behavior of TLD, it significantly can reduce the seismic response (displacement and base shear) of the structures.