• Title/Summary/Keyword: 진동대

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Harmonic Excitation of Shear Building with Force-Controlled Shaking Table (힘-제어 진동대를 이용한 전단건물의 조화진동)

  • Lee, Sang Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.1
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    • pp.853-859
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    • 2015
  • 1-DOF shear building was designed, built and tested to investigate the interactions between the shear building and the shaking table excited harmonically by the electro-magnetic forces. In the experiments horizontal accelerations of the shaking table and the shear building were measured. To understand the experimental results experimental setting was modeled as an unconstrained 2-DOF system under the hormonic forces. The responses of the shear building and the shaking table of the unconstrained 2-DOF system were found with the equations of motions. The magnification factors of the table and the shear building with respect to the amplitude of the harmonic forces and the transmission of the shear building with respect to the table excitations were found and compared with the experimental results.

Survey of Experimental Research Performed using Shaking Table Tests for Buildings in Korea (건축물의 진동대 실험을 이용한 국내 연구의 현황조사)

  • Lee, Han-Seon;Jung, Dong-Wook;Lee, Bo-Kyung;Kim, Hee-Cheul;Lee, Young-Hak;Lee, Ki-Hak
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.1-4
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    • 2008
  • This study serveys the state of research performed using the shaking tables available in Korea for buildings. First, the parameters to describe the capacity of shaking tables are introduced. Then major shaking tables available in Korea, the size of which is larger than 2m ${\times}$ 2m, are summarised. Finally, the papers published in Korea which used these shaking tables are introduced. It is expected that this servey could contribute to the more active use of shaking tables in the future seismic engineering research.

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Numerical Simulation on the Shaking Table Test considering Soil Structure Interaction (구조물과 지반의 동적 상호작용을 고려한 진동대 시험에 관한 수치 시뮬레이션)

  • Lee, Sung-Kyung
    • Journal of the Earthquake Engineering Society of Korea
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    • v.9 no.5 s.45
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    • pp.21-28
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    • 2005
  • This paper proposes a shaking table test considering the dynamic soil strcuture interaction (SSI) by using the accelerations measured from superstructure and shaking table. The proposed method based on the substructure method is that only superstructure is used as an experimental model and dynamic soil stiffness is reflected on the controller of shaking table for soil model. At the moment, an experimental superstructure is excited by a shaking table with the motion required to emulate the dynamic behavior of total SSI system. First, the validity of the proposed method is verified by the verification model of numerical simulation, which is derived from the equation of motion of SSI system under consideration. Also, the applicability of the proposed method to shaking table test is numerically verified from the simulation model incorporating the transfer function of shaking table.

Optimum positioning of friction support for vibration reduction in piping system (배관 진동저감 마찰 지지대 최적 위치 선정)

  • Jaeseok, Heo;Yong Hoon, Jang;Seunghun, Baek
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.6
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    • pp.680-690
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    • 2022
  • Vibrations in the pipe system trigger fatigue-related issues and lead to fatal other problems caused by pipe damage. There are numerous studies to analyze and reduce the cause of pipe vibration, among which a small number of studies are being conducted on pipe vibration reduction using friction supports. The study of friction supports, however, focused only on predicting and evaluating the performance of the friction supports and seldomly considered the design perspective of the install location of the supports. Therefore, this study intends to suggest the optimization process for finding the best installation region of friction support to attenuate the vibration of entire piping system. The optimal position of the friction support is predicted only by linear analysis to guarantee optimization efficiency in the design process. The designed friction support location is verified by time domain analysis.

Real-Time Hybrid Shaking Table Test of a Soil-Structure Interaction System with Dynamic Soil Stiffness (동적 지반강성을 갖는 지반-구조물계의 실시간 하이브리드 진동대 실험)

  • Lee, Sung-Kyung;Min, Kyung-Won
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.2
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    • pp.217-225
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    • 2007
  • This paper proposes the real-time hybrid shaking table testing methods to simulate the dynamic behavior of a soil-structure interaction system with dynamic soil stiffness by using only a structure model as the physical specimen and verifies their effectiveness for experimental implementation. Experimental methodologies proposed in this paper adopt such a way that absolute accelerations measured from the superstructure and shaking table are feedback to the shaking table controller, and then the shaking table is driven by the calculated motion of the absolute acceleration (acceleration feedback method) or the absolute velocity (velocity feedback method) of foundation that is required to simulate the dynamic behavior of a whole soil-structure interaction system. The shaking table test is implemented by reflecting the dynamic soil stiffness, which are differently approximated from the theoretical one depending on the feedback methods, on the shaking table controller to calculate soil part. The effectiveness of the proposed experimental methods is verified by comparing the response measured from the test on a foundation-fixed structural model and that obtained from the experiment of a soil-interaction system under the consideration in this paper and by matching the dynamic soil stiffness reflected on the shaking table controller with that identified using the experimentally measured data.

Dynamic Characteristic of the Seismic Performance of Uninterruptible Power Supply with Combined Isolator Using Shaking Table Test (복합면진장치를 적용한 무정전전원장치의 1축 진동대실험 기반 동적특성 분석)

  • Lee, Ji-Eon;Lee, Seung-Jae;Park, Won-Il;Choi, Kyoung-Kyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.26 no.1
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    • pp.19-28
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    • 2022
  • In this study, three types of combined isolator consisting of High Damping Rubber Bearing (HDRB) and wire isolator were developed for Uninterruptible Power Supply system (UPS). The dynamic characteristics of the combined isolator were investigated through one-axis shaking table test. The input acceleration were generated in accordance with ICC-ES AC156 code. Scale factors of the input acceleration were designed to be 0.5-2 times the required response spectrum defined in ICC-ES AC156. Based on the test results, damage and dynamic characteristics of the UPS were investigated: including natural frequency, damping ratio, acceleration time history response, dynamic amplification factor and relative displacement. Based on that, it was found that the combined isolator developed in this study could improve the seismic behavior of the UPS, in particular, the response acceleration.

6자유도 진동대 - 특성 및 활용방안

  • 이호섭
    • Journal of KSNVE
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    • v.1 no.1
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    • pp.7-19
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    • 1991
  • 해사기술연구소가 보유하고 있는 6자유도 대형진동대의 시스템 구성과 시험파형 합성기법 및 시험방법에 대하여 간략히 살펴보았다. 통상적인 가진기가 1방향의 운동만을 구현할 수 있음에 비해, 6자유도 진동대는 3축병진, 3축 회전의 임의의 복잡운동을 구현할 수 있는 국내 유일의 설비이며 용량 또한 30톤의 시험체까지를 대상으로 한 대형 진동대로서 각종 분야에 필요한 진동시험 업무를 지원할 수 있다. 구조물의 방진 및 내진설계를 위해서는 가능한한 실물 또는 모형의 실증실험이 필수적이며, 이는 내진 해석기법의 개발 및 검증의 기초가 된다. 특히 이 시스템은 내진 검증시험에 필요한 모든 기능을 갖추고 있으므로, 앞으로 건설될 국내원자력 발전소에 이용되는 각종기기의 내진검증시험을 통하여 이들 기기의 국산화에 크게 이바지할 것으로 보인다.

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Dynamic Test of Structural Models Using $4m{\times}4m$ Shaking Table ($4m{\times}4m$ 진동대를 이용한 구조모델의 동적실험)

  • 이한선;우성우;김병현
    • Journal of the Earthquake Engineering Society of Korea
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    • v.1 no.1
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    • pp.51-56
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    • 1997
  • The objective of this study is to review the current state of earthquake simulation tecniques using the shaking table and check the reliability. One degree-of-freedom(d.o.f) and three d.o.f aluminium shear models were used and $4m{\times}4m$ 6 d.o.f shaking table was excitated in one horizontal direction to simulate 1940 El centro earthquake accelerogram (NS component). When the actual acceleration history of shaking table is compared to the desired one, it can be found that the overall histories are very similar, but that the lower frequency range (0~2 Hz) of the actual excitation has generally lower amplitude than that of the desired in Fourier transform amplitude. Free vibration and white noise tests have shown almost the some values for natural frequencies, but shown quite different values for damping rations, that is, 1.37% in case of free vibration test vs 14.76 % in case of white noise test. The time histories of story shear driff show the globally linear elastic behaviors. But the elliptical shape of the histories with one of the axis being the stiffness of the story implies the effect of viscous damping.

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Development of composite sandwich equipment bay (샌드위치 복합재료 탑재부 개발)

  • Park, Jae-Sung;Jeong, Ho-Kyeong;Seo, Sang-Hyun;Yi, Yeong-Moo
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2005.11a
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    • pp.224-227
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    • 2005
  • KSL V-I 2단 탑재대를 복합재료 샌드위치 구조물로 설계/제작하였다. 축소형 탑재대를 제작하여 진동 특성을 측정하고, 측정된 결과를 이용하여 실물형 탑재대를 설계하였다. 탑재물의 중량을 포함하여 1차 고유진동수가 150 Hz가 되도록 설계하였으며 실제 시제를 제작하여 동특성을 측정하였다.

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Estimation of Aseismatic Performance of Laminated Rubber Bearing Through Shaking Table Tests (진동대 실험을 통한 적층고무받침의 내진성능 평가)

  • Park, Seong-Kyu
    • Journal of the Korean Society for Railway
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    • v.13 no.4
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    • pp.440-446
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    • 2010
  • This paper was investigated on the laminated rubber bearing, which mitigates damages of bridges from threat of earthquakes. Laminated rubber bearing can bear large loads for long periods of time and be capable of large deformations during an earthquake. To evaluate seismic isolation with laminated rubber bearing on several earthquake waves, we performed a shaking table test. In this test, deck acceleration was measured by accelerometers and shear force on piers was surveyed by load cells. Furthermore, seismic capacity of isolated systems with laminated rubber bearing was compared with non-isolated systems through shaking table test. The results show that deck acceleration and shear force were relatively reduced by laminated rubber bearing.