부가질량형 감쇠기의 현장실험을 통한 동특성추정

김홍진,조지성,주석준,황재승 한국풍공학회 2010 한국풍공학회지 Vol.14 No.1

For a secondary mass damper using liquid such as Tuned Mass Damper(TMD) or Tuned Liquid Column Damper(TLCD), it is impossible to fabricate the damper in factory for the identification of dynamic properties. Also, it is not easy to pre-fabricate a concrete Tuned Mass Damper(TMD) in factory, in which the moving mass is made of concrete. In this paper, a identification method of dynamic properties of secondary mass dampers based on in-situ experiment is presented. A decoupled equation of motion is derived from a coupled equation of motion of building and damper. The decoupled equation of motion is then applied to the system identification using the response of damper as an input and the response of building as an output. The proposed method is applied to numerical examples and an actual TMD and TLCD installed in buildings. TLD(Tuned Liquid Damper)나 TLCD(Tuned Liquid Column Damper)와 같이 액체를 질량체로 사용하는 부가질량형 감쇠기의 경우 동특성추정을 위하여 실제 크기의 진동제어기를 공장에서 제작하여 실험하는 것이 불가능하다. 또한 TMD(Tuned Mass Damper)의 질량체를 콘크리트로 사용하는 콘크리트 TMD의 경우에도 공장실험에서 콘크리트를 타설할 수 없기 때문에 완성된 TMD의 정확한 동적특성을 파악하는 것이 어렵다. 따라서 본 논문에서는 공장 가조립을 통한 실험을 실시하여 동적특성을 추정하기 어려운 경우에 대하여 현장실험을 통한 동특성추정 기법에 관하여 소개하고자 한다. 이를 위해 건물과 진동제어기의 연계된 운동방정식(Coupled equation of motion)으로부터 비연계 운동방정식(Decoupled equation of motion)을 유도한다. 유도된 비연계 운동방정식을 기반으로 건물의 응답과 진동제어기의 응답을 각각 시스템식별을 위한 입력과 출력으로 하여 일반적인 시스템기법을 이용하여 동특성을 추정할 수 있도록 한다.

TLCD와 TSD를 이용한 새로운 형태의 양방향 감쇠기 설계변수

민경원(Min, Kyung-Won) 한국소음진동공학회 2009 한국소음진동공학회 논문집 Vol.19 No.8

A new type bi-directional damper using a tuned liquid column damper(TLCD) and a tuned sloshing damper(TSD) is introduced in this study. Two dampers are usually needed to reduce wind-induced responses of tall buildings since they are along and across wind ones. The proposed damper has the advantage of controlling both responses with one damper. One of objectives of this study is to derive analytical dynamics to investigate coupled effects due to TLCD and TSD. Another objective is to address the effect of coupled control force due to TLCD and TSD on the dynamic characteristic of the damper based on analytical dynamics. Shaking table test is undertaken to experimentally grasp dynamic characteristics of the damper under white noise excitation. Its dynamic characteristic is expressed by the transfer function from the shaking table acceleration to the control force generated from the damper. Finally, its design parameters are identified based on the coupled dynamics, which include the mass ratio of horizontal liquid column to total liquid for a TLCD, the participation factor of the fundamental liquid sloshing for a TSD and damping ratio for both cases.

초고층 건물의 양방향 풍응답 제어를 위한 액체댐퍼 실험

이혜리(Lee, Hye-Ri),민경원(Min, Kyung-Won) 한국소음진동공학회 2010 한국소음진동공학회 논문집 Vol.20 No.3

This study deals with the design of a bi-directional damper using a tuned liquid damper(TLD) and a tuned liquid column damper(TLCD) for a SDOF building. Two dampers are usually needed to reduce wind-induced responses of tall buildings since they are along and across wind ones. The proposed damper has the advantage of controlling both responses with a single damper. The damper used in this study behaves as both a TLCD in a specific translational direction and a TLD in the other orthogonal direction. This paper presents experimental verification to confirm its control performance. First, shaking table test is carried out to investigate reducing responses by the damper. Control performance of the damper is expressed by the transfer function from shaking table accelerations to SDOF building ones. Testing results show that the damper reduced bi-directional responses of a SDOF building. Also, it reduced torsion responses.

Pedestrian- and wind-induced bi-directional compound vibration control using multiple adaptive-passive TMD-TLD system

Ying Zhou,Liangkun Wang,Weixing Shi 국제구조공학회 2024 Smart Structures and Systems, An International Jou Vol.33 No.6

To control vertical and lateral compound vibration simultaneously using an integrated smart controller, passive tuned mass damper (TMD) and tuned liquid damper (TLD) are updated and combined to an adaptive-passive TMD-TLD (APTMD-TLD) system. As for the vertical AP-TMD part on top of the vertical spring, it can retune itself through varying the level of liquid in the tank to adjust its mass, while the lateral AP-TLD part at the bottom of the vertical spring can retune itself by changing the level of liquid. Further, for multimodal response control, the multiple AP-TMD-TLD (MAP-TMD-TLD) system is proposed as well. Each AP-TMD-TLD in the system can identify the structural vertical and lateral modal frequencies through the wavelet-transform (WT) based algorithm and retune its vertical and lateral natural frequencies both through adjusting the level of liquid in the AP-TMD and AP-TLD parts respectively. A cantilever cable-stayed landscape bridge which is sensitive to both human-induced and wind-induced vibrations is presented as a case study. For comparison, initial parameters of MAPTMD-TLD are mistuned. Results show that the presented system can retune its vertical and lateral frequencies precisely, while the retuned system has a better bi-directional compound control effect than the mistuned system before the retuning operation and can improve the serviceability significantly.

건축구조물의 2방향 진동제어를 위한 동조액체질량감쇠기

허재성(Heo, Jae-Sung),박은천(Park, Eun-Churn),이상현(Lee, Sang-Hyun),이성경(Lee, Sung-Kyung),김홍진(Kim, Hong-Jin),조봉호(Cho, Bong-Ho),조지성(Jo, Ji-Seong),김동영(Kim, Dong-Young),민경원(Min, Kyung-Won) 한국소음진동공학회 2008 한국소음진동공학회 논문집 Vol.18 No.3

This paper presents a design of a tuned liquid mass damper(TLMD) for controlling bi-directional response of high-rise building structure subjected to windload. The proposed damper behaves as a tuned mass damper(TMD) of which mass is regarded as the mass of a tuned liquid column damper(TLCD) and the case wall of the TLCD itself in one direction and the TLCD in the other direction. Because the proposed device has coupled design parameter along two orthogonal directions, it is very important to select designing components by optimal fine tuning. In the designing TLMD, for easy maintenance, the rubber-bearing with small springs was applied in TMD direction. In this study, the Songdo New City Tower 1A in Korea, which has been designed and constructed two TLCDs in order to control bi-directional response, was chosen as the model building structure. The results of rotation test proved the effectiveness of bi-directional behavior of TLMD.

Seismic control of structures using sloped bottom tuned liquid dampers

Amardeep D. Bhosale,Mohan M. Murudi 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.2

Earlier numerous studies have been done on implementation of Tuned Liquid Damper (TLD) for structural vibration control by many researchers. As per current review there is no significant study on a sloped bottom TLD. TLD‟s are passive devices. A TLD is a tank rigidly attached to the structure and filled partially by liquid. When fundamental linear sloshing frequency is tuned to structure‟s natural frequency large sloshing amplitude is expected. In this study set of experiments are conducted on flat bottom and sloped bottom TLD at beach slope 20º, 30º and 45º, for different types of structures, mass ratio, and depth ratio to investigate the overall effectiveness of TLD and specific effect of TLD parameters on structural response. This experimental study shows that a properly designed TLD reduces structural response. It is also observed that effectiveness of TLD increases with increase in mass ratio. In this experimental study an effectiveness of sloped bottom TLD with beach slope 30º is investigated and compared with that of flat bottom TLD in reducing the structural response. It is observed from this study that efficiency of sloped bottom TLD in reducing the response of structure is more as compared to that of flat bottom TLD. It is shown that there is good agreement between numerical simulation of flat bottom and sloped bottom TLD and its experimental results. Also an attempt has been made to investigate the effectiveness of sloped bottom TLD with beach slope 20º and 45º.

Tuned Liquid Damper 와 Active Mass Damper를 결합한 Hybrid 진동 제어 방법 개발

곽문규(Moon K. Kwak),신지환(Ji-Hwan Shin) 한국소음진동공학회 2019 한국소음진동공학회 학술대회논문집 Vol.2019 No.2

Vibration control of a structure by a tuned liquid column damper with embossments

Park, ByungJin,Lee, YongJae,Park, MinJae,Ju, Young K. Elsevier 2018 ENGINEERING STRUCTURES Vol.168 No.-

<P><B>Abstract</B></P> <P>Several studies have examined damping mechanisms to improve damping effects in a tuned liquid column damper (TLCD). The additional damping mechanisms include orifices, valves, and the use of highly viscous liquids. In the present study, in contrast to previous studies, a damping mechanism using embossments on the wall of the TLCD was proposed, and TLCD with embossment (termed as ETLCD) was proposed as a new type of passive damper. The study focuses on an experimental evaluation of the dynamic characteristics of ETLCD and vibration control performance for tall buildings with ETLCD by using a shaking table. Thus, a characteristic experiment was performed with the presence of embossments, total length of the liquid column, and an excitation amplitude ratio as variables. Additionally, a scaled model test of the SDOF building composed of a free vibration test and sine sweep forced vibration test was conducted to verify the vibration control performance of the structure with ETLCD. Consequently, the equivalent damping ratios of conventional TLCD and ETLCD were experimentally compared, and the theoretical natural frequency of TLCD was re-evaluated in the characteristic experiment. Furthermore, the results of the scaled model test indicated that the vibration control performance of the ETLCD was superior to that of the conventional TLCD in terms of response reduction, efficiency, and stability.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The ETLCD exhibited non-linearity similar to that of conventional TLCD. </LI> <LI> The evaluation equations of the equivalent damping ratio were proposed. </LI> <LI> Experimental natural frequencies of TLCD and ETLCD were overestimated. </LI> <LI> The adjusting factor for calculating effective length was proposed. </LI> <LI> The control performance of ETLCD was superior to that of conventional TLCD. </LI> </UL> </P>

동조액주관댐퍼의 고유진동수와 오러피스에 대한 감쇠 특성

유기표(You Ki-Pyo) 대한건축학회 2010 大韓建築學會論文集 : 構造系 Vol.26 No.4

Orifices are installed on the horizontal tube of a tuned liquid column damper in order to increase the coefficient of head loss of the damper. Because such orifices control the flow of the horizontal tube, there is a variation in the level of water in the vertical tube. In general, only one orifice is installed in the middle for controlling the flow of the horizontal tube. In this study, examined the damping characteristic of a tuned liquid column damper according to porosity, the number of orifices installed and natural frequency. Amplitude response was lower when orifices were not installed than when they were, and the lower amplitude response increased the head loss coefficient. Compared to when only one installed, when two orifices were installed amplitude response decreased by up to 7%.

내부 슬로싱 현상을 이용한 사각상자 형태의 부유체 Sway 거동 모사에 대한 수치적 고찰

하민호(Minho Ha),정철웅(Cheolung Cheong) 한국소음진동공학회 2013 한국소음진동공학회 학술대회논문집 Vol.2013 No.4

In this paper, possibility of controlling motion of a floating structure using a tuned liquid damper (TLD) is numerically investigated. A TLD is a tank partially filled with liquid. Sloshing phenomena of liquid inside a tank can suppress movement of the tank subject to external excitations at specific frequency. The effects of sloshing phenomena inside a rectangular floating body on its sway motion are investigated by varying excitation frequency. First, a grid-refinement study is carried out to ensure validity of grid independent numerical solutions using present numerical techniques. Then, sway motion of the floating body subjected to wave with five different frequencies are simulated. The normalized amplitudes of sway motion of the target floating body are compared over the frequency, for cases with and without water inside the floating body. It is shown that the motion of the floating body can be minimized by matching the sloshing natural frequency to excitation frequency.