Experimental study on annular cylindrical tuned liquid dampers for vibration control under different excitation angles

Abstract

This work aims to experimentally show the effectiveness of annular cylindrical tuned liquid dampers (ACTLDs) on the classical tuned liquid column dampers (TLCDs) under the effect of inclined ground motion. For experimental measurements, a single-story model structure constituted by two plates at the top and bottom connected by four columns was constructed. Since the water length within the tuned liquid dampers (TLDs) is a very important parameter that affects the performance of the absorber, ACTLD and TLCD devices were designed such that their total water lengths be equal for comparison purposes. The modal characteristics of the model structure were determined by ambient vibration tests. The resonant frequency, head-loss coefficient, damping ratio, and water height-frequency diagram of ACTLD and TLCD devices were obtained experimentally through the shaking table tests. Then, the shaking table tests on the model structure with and without the absorbers under consideration were performed to obtain the acceleration and displacement time-histories and the damping ratio for the coupled system. In experimental tests, different excitation directions from 0 to 90 deg were considered. Results of the study show that ACTLDs are better than TLCDs at suppressing vibrations caused by ground motions acting on the structure at oblique angles.