• Title/Summary/Keyword: 진동하는 구

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Optimal Design of Viscoelastic Dampers in Building Frames by Eigenvalue Assignment (건축구조물에서 고유값 지전에 의한 점탄성 감쇠기의 최적설계)

  • Son, Dong-In;Lee, Sang-Hyun;Park, Ji-Hun;Kim, Jin-Koo
    • Journal of the Earthquake Engineering Society of Korea
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    • v.5 no.2
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    • pp.125-138
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    • 2001
  • 고유진동수와 감쇠비는 지진이나 바람과 같은 동적 횡하중에 대해 구조물의 응답을 결정하는 주요한 특성이다. 본 연구는 지진하중에 대하여 목표응답 수준을 만족하는 구조물의 고유진동수와 감쇠비를 지정하고, 이 값을 실현하는 점탄성 감쇠기 파라미터의 처적분포를 구하는 설계방법을 제안한다. 여기서 지정할 고유진동수와 감쇠비는 목표응답 수준을 만족하는 여러 조합 중 설계조건과 원래 건물의 특성에 따라 결정될 수 있다. 제안한 설계방법은 점탄성 감쇠기의 감성 파라미터를 고유값의 기울기 정보를 바탕으로 분포시키므로 최적 위치와 크기에 대한 정보를 동시에 제공한다. 예제로서 평면 10층 전단 건물을 대상으로 최적설계를 수행하여 지정된 고유값을 실현하는 파라미터의 최적분포를 구하고 이를 통해 제안한 최적 설계의 특성을 확인하였다. 또한 더 나아가 3차원 일방향 비대칭 전단전물에 제안된 최적설계를 수행하여 그에 대한 적용가능성을 확인하였다.

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An Investigation on the Assessment Method of Ship's Vibration Concerning Habitability(ISO6954:2000) (선박 거주구 진동(ISO6954:2000)의 평가 방법에 대한 고찰)

  • Kim, Jun-Seong;Kim, Tae-Eun;Lee, Il-Oh;Lee, Don-Chool
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.04a
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    • pp.772-778
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    • 2011
  • ISO6954:2000 (Mechanical vibration - Guidelines for the measurement, reporting and evaluation of vibration with regard to habitability on passenger and merchant ships) has taken effect as the governing body for vibration regarding habitability due to ship vibration. However, ISO6954:2000, when compared ISO6954:1984 (the first draft of ISO6954), needs to clear some deficiencies concerning convenience and reliability during field applications. In this paper, ISO6954:1984 and 2000 are evaluated on their suggested assessment method of ship's vibration in the future.

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A Study of Preventing Pressure Oscillation for Supersonic Inlet of IRR at the Boosting Mode (부스팅 모드에서 IRR(Integral Rocket Ramjet) 초음속 흡입구의 압력진동 감쇄 방안 연구)

  • Park, Geun-Hong;Yoon, Hyun-Gull;Lim, Jin-Shik
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.563-564
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    • 2010
  • A Numerical analysis of preventing pressure oscillation for the supersonic inlet of IRR at the boosting mode was conducted in this study. To reduce the fluctuation of pressure, the supersonic inlet was equipped with annular slit. By decreasing the entrained air mass, the amplitude of fluctuation and maximum pressure at the inlet were decreased while the frequency was increased. In case, the optimal trade-off value is obtained between frequency and amplitude, it is expected that the pressure oscillation declining method using the slit will be helpful in various boosting and transition mode problem for IRR.

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The Optimum Structure Modification by Shape Changes (형상변경에 의한 최적구조변경법)

  • 박석주;오창근
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1994.10a
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    • pp.225-230
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    • 1994
  • 본 연구에서는 진동특성을 개선하기 위한 방법으로서 구조물이 가지는 공간적인 좌표를 설계변수로 하여 감도를 구하고, 이를 이용하여 구조물의 길이와 높이에 대한 형상을 변경하는 최적구조변경법에 대해 예시하고자 한다. 먼저 모우드합성법을 이용하여 임의 치수의 L형 구조물의 진동특성을 해석하고, 진동 특성을 변경하기 위해 감도해석법으로 변경할 부분의 감도를 구하여 변경할 부분의 변경량을 계산한다. 그리고 변경한 후 재해석을 통해 결과를 비교함으로써 제시한 방법의 타당성을 고찰하고자 한다.

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Analytical Study on the Isolation Effects of Bore Holes by Materials (진동차단공의 재료별 방진효과에 관한 해석적 연구)

  • Lee, Kang-Il
    • Journal of the Korean Geosynthetics Society
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    • v.5 no.2
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    • pp.23-30
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    • 2006
  • This paper aims at investigating the material and dimensions of a wall barrier such as installation depth, thickness, and distance from vibration source by means of finite element method (FEM). In this study, various materials such as concrete, EPS, and steel were adopted. The results showed that the efficiency of a wall barrier appears to be more dependent on installation depth than thickness. In addition, a concrete wall barrier is less efficient than any other wall barrier. In contrast, EPS wall barriers seem to be much sensitive to the wall thickness than the depth.

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Dynamic Load Factor for Floor Vibration due to Lively Concerts (공연하중에 의한 바닥진동 설계용 동하중계수)

  • Hong, Kap Pyo;Yoon, Kwang Sup
    • Journal of Korean Society of Steel Construction
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    • v.14 no.6
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    • pp.721-728
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    • 2002
  • Modern structrues are being built using high-strength and light-weight construction materials resulting in decreased structural mass and damping properties. Rhythmic activities such as jumping, dancing and clapping during lively concerts can produce excessive vibration of steel structures. In this study, dynamic load factors that occur during lively concerts were presented through vibration test and real-time monitoring of an existing concert hall. The vibration test included modal analysis and jumping test according to the forcing frequencies and the number of participants. Dynamic load foactors were acquired directly from peak acceleration responses of each harmonics. Comparing NBCC 1995, the 3rd harmonic must be included in the design of concert halls. Dynamic load factors must be increased as a result of the vibration test.