Seismic response control with density-variable tuned liquid dampers

In this paper,the seismic effectiveness of a density-variable tuned liquid damper(DVTLD) with a sloping bottom is experimentally investigated through a series of shake table tests on a 1/4-scale,3-story frame structure and numerically simulated by a new semi-analytical model.Special attention was given to reducing the fi rst peak and maximum response under near-and far-fi eld ground motions,and the robustness of a density-variable control system consisting of multiple DVTLDs with closely-spaced frequencies.Adaptable to earthquake excitations,the density-variable control system has been demonstrated to be more effective and more robust than its corresponding traditional tuned liquid damper in suppressing story drift and floor acceleration of the structure.Numerical simulations of the DVTLD-controlled structure agreed very well in phase with experimental results but somewhat overestimated the amplitude of the structural response.