In this study, nonlinear dynamic characteristics of a tuned liquid column damper (TLCD) varying with the amplitude of excitation input are evaluated through shaking table tests and numerical model of a TLCD. The tuned mass damper (TMD) analogy of a TLCD is used to simplify the formulation, in which involves equivalent viscous damping of the inherent nonlinear damping term of a TLCD. The equivalent TMD model of a TLCD shows that the dynamic behavior of a TLCD is affected by the natural frequency, the damping ratio and the ratio of total liquid mass to the mass in horizontal column of a TLCD. Shaking table test is performed to obtain experimental transfer functions that describe the dynamic behavior of a TLCD specimen subjected to a harmonic loading with various excitation amplitudes. Transfer functions for various excitation amplitudes are measured from shaking table acceleration to both the liquid displacement within a TLCD container and the control force produced by a TLCD specimen. Also, the dissipation energy due to the inherent damping of a TLCD is measured from the shaking table test varying with excitation amplitude. The variation of design parameters of a TLCD according to the excitation amplitude is investigated by comparing the transfer functions obtained from the shaking table test to those derived from the TMD analogy of a TLCD. These results showed that both the natural frequency and the mass ratio of a TLCD are independent on the variation of excitation amplitude, while the damping ratio of a TLCD increases with larger excitation amplitude.

The objective of this study is to investigate design parameters of a tuned liquid column damper(TLCD), which is affected by various excitation amplitudes, through shaking table test. Design parameters of a TLCD are examined based on the equivalent tuned mass damper(TMD) model of a TLCD, in which the nonlinear damping of a TLCD is transposed to equivalent viscous damping. Shaking table test is carried out for a TLCD specimen subjected to harmonic waves with various amplitudes. Transfer functions are ratios of liquid displacement of TLCD and control force produced by a TLCD, respectively, with respect to the acceleration excited by a shaking table. They are derived based on the equivalent TMD model of a TLCD. Then, the variation of design parameters according to the excitation amplitude is examined by comparing analytical transfer functions with experimental ones. Finally, the dissipation energy due to the damping of a TLCD, which is experimentally observed from the shaking table test, is examined according to the excitation amplitude. Comparisons between test results and analytical transfer functions showed that natural frequencies of TLCD and the ratio of the liquid mass in a horizontal column to the total liquid mass does not depend on the excitation amplitude, while the damping ratio of a TLCD increases with larger excitation amplitudes.

The purpose of this study is to verify the transfer function of input acceleration and output control force based on linearizing a damping term of Tuned Liquid Column Damper(TLCD) with nonlinearity analytically. In addition, analysis is conducted for dynamic characteristics according to the design parameter such as section ratio of both vertical and horizontal column and the level of liquid in the vertical column which is used for tuning method. The dynamic characteristics is identified by the analysis for the natural frequency, damping ratio and effective mass ratio of TLCD and a shaking table test for the transfer function. The results indicates that the level of liquid and section ratio affect the characteristics of damping ratio and mass ratio. Damping and mass ratio increase as the section of vertical column of TLCD decreases due to turbulence in the elbow of TLCD.

This paper proposes a tuned liquid column sloshing damper(TICSD) and its optimal design to mitigate bidirectional responses of building structures. The proposed damper acts as a liquid column vibration absorber (LCVA) and a tuned sloshing damper(TSD), respectively, in both principal axes of building structures. Optimum designs of the TLCSD addresses the minimizing in terms of live load, area and volume due to its installation, comparing to each installation with two dampers in two principal directions, respectively. Numerical results from optimum designs shows that the control robustness due to changes in the effective column length and the effective mass of the TLCSD superiors to that uses the head loss coefficient and damping nets in an existing liquid column vibration absorber(LCVA) and TSD. The TLCSD is designed according to the similarity laws of 76 story benchmark building model. Numerical model of the proposed TLCSD is derived based on the experimentally obtained transfer functions according to rotational angles.

본 연구에서는 동조질량감쇠기(TMD)와 동조액체 기둥감쇠기(TLCD)로 구성된 2방향 감쇠기의 제어성능을 실험적으로 검증하였다. 본 연구에 사용된 감쇠기는 한방향으로는 TMD로 거동하고, 다른 직교하는 방향에서는 TLCD로 거동하여 제어력이 발생하는 감쇠기이다. 우선, 제작된 감쇠기의 동적특성과 TMD와 TLCD에 의해 발생하는 제어력들의 연계효과를 조사하기 위한 진동대 실험을 수행하였다. 다음으로 이러한 실험결과를 바탕으로 감쇠기의 동적특성에 영향을 미치는 파라미터를 정량적으로 평가하였다. 본 연구에서 사용된 감쇠기가 입사각을 갖는 진동에 의해 가진될 때 TMD와 TLCD에 의해 연계된 제어력이 발생하는 것을 진동대 실험결과로부터 확인하였다. 또한, 감쇠기가 건축물의 2방향 응답제어에도 효과적으로 사용될 수 있음을 확인하였다.

This paper presents equivalent linear system for 76-story benchmark building with nonlinear tuned liquid column damper (TLCD). The response characteristic of benchmark building for the deterministic wind loads is investigated. And then, the equivalent linear system is obtained first in terms of equivalent linear damping and second in terms of equivalent single degree of freedom system. Numerical results show that these equivalent linear systems can almost exactly predict the controlled structural responses when compared with the nonlinear TLCD system. Finally, an equation for estimating the peak response of structure subjected to harmonic load is derived. This equation does not require any iteration process which is essential in the analysis using equivalent linear system for TLCD.

In this study, the control perfomances of Tuned Mass Damper (TMD) and Tuned Liquid Column Damper (TLCD) are evaluated and compared for seismically excited structures. Results show that TLCD is more effective than TMD for interstory drift control while TLCD is as effective as TMD for acceleration control. In special, it is shown that interstory drifts are maximally controlled in lower floors and accelerations are reduced most in upper floors. This indicates that TLCD is an effective controller for earthquake-induced structures in terms of structural safety as well as serviceability.