• Title, Summary, Keyword: 동조액체 기둥감쇠기

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Development of Variable Voltage Sensing for Identification of Dynamic Characteristics of TLCDs (동조액체기둥감쇠기의 동적특성을 파악하기 위한 가변전압측정 시스템 개발)

  • Jang, Seok-Jung;Kim, Jun-Hee;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.3
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    • pp.275-281
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    • 2015
  • In this study, vertical motion of a Tuned Liquid Column Damper(TLCD) is measured by a variable voltage measurement system in the electric field and design parameters of the TLCD are determined. First, nonlinear damping term of the TLCD is replaced as the equivalent viscous damping term. The natural frequency and damping ratio of dynamic characteristics of the TLCD are verified. In addition, a novel liquid level measurement system is developed for measuring vertical motion of the TLCD. For the experimental achievement, experimental characterizations of natural frequency and damping ratio of the TLCD are undertaken utilizing the developed variable voltage sensing. Also, shake table testing is performed to determine the dynamic characteristics of the TLCD. As a result, the feasibility of the proposed liquid level measurement system is verified by comparison with the capacitive type wavemeter.

Experimental Evaluation of Design Parameters for TLCD and LCVA (TLCD와 LCVA의 설계파라미터에 대한 실험적 평가)

  • Lee, Sung-Kyung;Min, Kyung-Won;Park, Ji-Hun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.5
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    • pp.403-410
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    • 2009
  • In this paper, damping coefficients and effective masses of tuned liquid-type column dampers were quantitatively evaluated based on experimental results by using system identification technique. First, shaking table tests were performed for two types of tuned liquid-type column dampers. Then, the dynamic characteristics of dampers used in this study were experimentally grasped from harmonic wave excitation testing results of the dampers with various water level. Finally, damping ratios and effective masses of the dampers with varying water level were quantitatively evaluated from minimizing the errors between numerical and experimental results. It was confirmed from system identification results that damping ratio and effective mass are decreased as the water level of dampers is increased.

Dynamic Characteristic of A Bi-dirctional Damper Using A Tuned Mass Damper and A Tuned Liquid Column Damper (TMD와 TLCD를 이용한 2방향 감쇠기의 동적특성)

  • Lee, Sung-Kyung;Min, Kyung-Won;Park, Eun-Churn
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.6
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    • pp.589-596
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    • 2008
  • This study introduces the design of a bi-directional damper using a tuned mass damper(TMD) and a tuned liquid column damper(TLCD) and presents experimental verifications to confirm its control performance. The damper used in this study behaves as a TMD in a specific translational direction and acts as a TLCD in the other orthogonal direction. First, shaking table test is performed to investigate the coupled effect of control forces produced by TMD and TLCD. Then, the parameters that affect to dynamic characteristics of the proposed damper are quantitatively evaluated based on the experimental results. Testing results shows that the damper used in this study produces control forces coupled by TLCD and TMD, as it is excited by waves with an incident angle. Also, it is observed that the damper can be used to reduce bi-directional responses of building structures.

Performance Test of a Tuned Liquid Mass Damper installed in a Real-Scaled Structure (실물크기 구조물에 설치된 동조액체질량감쇠기의 성능실험)

  • Heo, Jae-Sung;Park, Eun-Churn;Lee, Sung-Kyung;Lee, Sang-Hyun;Kim, Hong-Jin;Jo, Ji-Seong;Cho, Bong-Ho;Joo, Seok-Jun;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.21 no.2
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    • pp.161-168
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    • 2008
  • In this paper, a tuned liquid mass damper(TLMD) was proposed and experimentally investigated on its control performance, which can control bi-axial responses of building structures by using only one device. The proposed TLMD controls the structural response in a specific one direction by using a liquid sloshing of TLCD. Also, the TLMD reduces the response of structures in the other orthogonal direction by behaving as a TMD that uses mass of the container itself and liquid within container of TLCD installed on linear motion guides. Force-vibration tests on a real-sized structure installed with the TLMD were performed to verify its independent behavior in two orthogonal directions. Test results showed that the responses of a structure were considerably reduced by using the proposed TLMD and its usefulness for structural control in two orthogonal directions.

Design Parameter Identification Using Transfer Function of Liquid Column Vibration Absorber (LCVA) (전달함수를 이용한 LCVA의 설계변수 분석)

  • Lee, Sung-Kyung;Min, Kyung-Won;Chung, Hee-San
    • Journal of the Earthquake Engineering Society of Korea
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    • v.13 no.4
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    • pp.47-55
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    • 2009
  • The purpose of this study is to verify the transfer function of input acceleration and output control force by linearizing a velocity-dependent damping term of Liquid Column Vibration Absorber (LCVA). Analytical and experimental research is conducted to identify natural frequency, damping ratio and participated mass ratio of LCVA with various section ratios of vertical and horizontal areas. Findings obtained experimentally by the shaking table test are compared with analytical findings using optimization technique with constraints. The results indicate that the level of liquid and section ratio of LCVA affect the characteristics of damping ratio and mass ratio. Damping and mass ratio increase as the section of vertical column of LCVA decreases, due to turbulence in the elbow of LCVA.

Performance Test of a Tuned Liquid Mass Damper installed in a Real-Scaled Structure (실물크기 구조물에 설치된 동조액체질량감쇠기의 성능실험)

  • Heo, Jae-Sung;Park, Eun-Churn;Lee, Sang-Hyun;Lee, Sung-Kyung;Min, Kyung-Won;Kim, Hong-Jin;Jo, Ji-Seong;Cho, Bong-Ho;Joo, Seok-Jun
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.449-457
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    • 2008
  • In this paper, a tuned liquid1) mass damper(TLMD) was proposed and experimentally investigated on its control performance, which can control bi-axial responses of building structures by using only one device. The proposed TLMD controls the structural response in a specific one direction by using a liquid sloshing of TLCD. Also, the TLMD reduces the response of structures in the other orthogonal direction by behaving as a TMD that uses mass of the container itself and liquid within container of TLCD installed on linear motion guides. Force-vibration tests on a real-sized structure installed with the TLMD were performed to verify its independent behavior in two orthogonal directions. Test results showed that the responses of a structure were considerably reduced by using the proposed TLMD and its usefulness for structural control in two orthogonal directions.

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Dynamic Characteristics of Tuned Liquid Column Dampers Using Shaking Table Test (진동대실험에 의한 동조액체기둥감쇠기의 동적특성)

  • Min, Kyung-Won;Park, Eun-Churn
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.6
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    • pp.620-627
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    • 2009
  • Shaking table test was carried out to obtain dynamic characteristics of TLCDs with uniform and non-uniform sections for both horizontal and vertical tubes. The input to the table is harmonic acceleration with constant magnitude. The output is horizontal dynamic force which is measured by load cell installed below the TLCD. Transfer functions are experimentally obtained using the ratio of input and output. Natural frequency, the most important design factor, is compared to that by theoretical equation for TLCDs with five different water levels. System identification process is performed for experimentally obtained transfer functions to find the dynamic characteristics of head loss coefficient and effective mass of TLCDs. It is found that their magnitudes are larger for a TLCD with non-uniform section than with uniform section and natural frequencies are close to theoretical ones.

Measurement of Liquid Oscillation in Tuned Liquid Dampers using a Laser Doppler Vibrometer (레이저진동계를 사용한 동조액체댐퍼의 액체 진동 측정)

  • Shin, Yoon-Soo;Min, Kyung-Won;Kim, Junhee
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.29 no.6
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    • pp.513-519
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    • 2016
  • In this study, dynamic vertical displacement of liquid in the tuned liquid column damper(TLCD) is measured by a laser Doppler vibrometer(LDV) to overcome limitations of existing sensors and to leverage noncontact sensing. Addressing advantages of noncontact measurements, operational principles of the LDV to measure velocity and displacement of a target object in motion is explained. The feasibility of application of the LDV to measurement of liquid motion in the TLCD is experimentally explored. A series of shake table tests with the TLCD are performed to determine requirements of application of the LDV. Based on the experimental results, it is proved that the LDV works under the condition of adding dye to the liquid by increasing the intensity of reflected laser and thus validity is verified by comparison with a conventional wave height meter.

Experiment of a Liquid Damper Controlling Bi-directional Wind Responses of a Tall Building (초고층 건물의 양방향 풍응답 제어를 위한 액체댐퍼 실험)

  • Lee, Hye-Ri;Min, Kyung-Won
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.3
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    • pp.287-295
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    • 2010
  • 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.

Experimental Performance Evaluation of a 2-way TLMD using a TLCD and a Rubber Bearing-type TMD (TLCD와 고무패드형 TMD를 이용한 2방향 TLMD의 성능평가실험)

  • Heo, Jae-Sung;Kim, Hong-Jin;Jo, Bong-Ho;Jo, Ji-Seong;Park, Eun-Churn;Lee, Sang-Hyun;Lee, Sung-Kyung;Kim, Dong-Young;Min, Kyung-Won
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.465-470
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    • 2007
  • In this paper, a two-way tuned liquid mass damper(TLMD) using a tuned liquid column damper(TLCD) and a rubber-bearing-type tuned mass damper(TMD) was manufactured for controlling two-way direction acceleration responses of a high-rise building structure. The proposed controlling device behaves as a tuned liquid column damper in one direction and as a tuned mass damper in the other direction. In this study, Performance evaluation of the downscaled model is conducted. The results show that the two-way controllability is behaved independently each other and realscale TLMD applicable to the high-rise building can be designed.

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