• Title/Summary/Keyword: Vibrational Characteristics

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Characteristics of Flow-induced Vibration for CE Type Steam Generator Tube with Various Column and Row Number (CE형 증기발생기 전열관의 행열 변화에 따른 유체유발진동 특성)

  • Ryu, Ki-Wahn;Cho, Bong-Ho;Park, Chi-Yong;Park, Su-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11b
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    • pp.927-932
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    • 2002
  • The stability ratio and vibrational amplitude of each tube inside a steam generator have different values. We estimate the characteristics of flow-induced vibration for CE type steam generator with various column and row number of the tube. To obtain the thermal-hydraulic data and stability ratio we use the ATHOS3-MODI and PIAT-FEI/TE code respectively. It turns out that the steam generator has a bounded central zone with the distributed values of the stability ratio and the vibrational amplitude, and those values across the zone boundary become decreased.

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Structural and Vibration Characteristics for the Scaffolding System of LNG Cargo Containment (LNG 화물창 비계 시스템의 구조해석 및 진동 특성)

  • Oh, B.J.;Ryu, B.J.;Lee, Y.S.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.20 no.6
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    • pp.546-554
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    • 2010
  • The paper deals with the structural analysis and vibration test for the scaffolding system of LNG cargo containment. The eight-stories scaffolding system has telescopic area, working area, coner area and storage area in real system. In the structural analysis, the maximum displacement and stress of the each floor for the scaffolding system are investigated by finite element method. In the vibrational analysis, the natural frequencies and mode shapes for 8-stories scaffolding system of the LNG cargo containment are investigated. In order to compare theoretical natural frequencies with experimental ones, small size of 2-step scaffolding structure is used, and the theoretical results for natural frequency have a good agreement with experimental ones.

A Study on the Vibrational Characteristics of a Foot Mount Type Gearbox for Epicyclic Gear Train (바닥고정형 유성기어박스의 진동특성에 관한 연구)

  • Lee, Dong-Hwan;Yun, In-Seong;Cheon, Gil-Jeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.10 s.181
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    • pp.2619-2627
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    • 2000
  • In this paper, the vibrational characteristics of a foot mount type gearbox for epicyclic gear train have been studied. The modal parameters and mode shapes of a gearbox have been computed using AN SYS code. Modal testing was carried out to verify the FEM analysis model. It has been shown that the analysis results are in good agreements with the experimental results. Harmonic analysis has been executed to verify the effect of thickness variance of gearbox housing on the modal response. Analyzing the calculated results, some guides for optimal vibration response has been deduced.

Characteristics of Flow-induced Vibration for CE Type Steam Generator Tube with Various Column and Row Number (CE형 증기발생기 튜브의 행열 변화에 따른 유체유발진동 특성)

  • Ryu, Ki-Wahn;Cho, Bong-Ho;Park, Chi-Yong;Park, Su-Ki
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.390.2-390
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    • 2002
  • The stability ratio and vibrational amplitude of each tube inside a steam generator have different values. We estimate the characteristics of flow-induced vibration for CE type steam generator with various column and row number of the tube. To obtain the thermal-hydraulic data and stability ratio we use the ATHOS3 and PIAT-FEI/TE code respectively. It turns out that the steam generator has a bounded central zone which the distributed values of the stability ratio and the vibrational amplitude, and those values across the zone boundary become decreased.

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Evaluating the Vibrational Characteristics of Floor Impact Noise in Different Structural Elements of an Apartment House (바닥충격에 의한 공동주택의 바닥, 벽, 천장의 진동 및 소음방사특성 연구)

  • Lee, Byung-Kwon;Jeon, Jin-Yong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.351.2-351
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    • 2002
  • The overall noise reduction was compared in regard to the vibrational characteristics of floor impact noise in a multi story residential building which has several noise reduction treatments. The vibration through its structural elements such as wall, floor and ceiling and sound emitting were investigated for each insulation treatment. It was found that, in case of heavy-weight impact noise, the vibration energy is emitted mostly from ceiling, but for the light-weight impact noise, most of the energy comes through ceiling and walls. (omitted)

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A Study on the Vibrational Characteristics of a Gearbox for Epicyclic Gear Train (유성기어박스의 진동특성에 관한 연구)

  • Lee, Dong-Hwan;Youn, In-Seong;Cheon, Gill-Jeong
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.837-842
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    • 2000
  • In this Paper, the vibrational characteristics of a gearbox for epicyclic Rear train have been studied The modal parameters and mode shapes of a gearbox have been computed using ANSYS code. Modal testing was carried out to verity the FEM analysis model. It has been shown that the analysis results are m good agreements with the experimental results. Harmonic analysis has been executed to verify the effect of thickness variance of gearbox housing on the modal response. Analyzing the calculated results, some guides fer optimal vibration response has been deduced.

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Prediction of Dynamic Characteristics of Continuous Structures due to the Modification of Stiffness (강성 변경에 따른 연속체 구조물의 동특성 변화 예측)

  • Lee, Jung-Youn
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.6 no.3
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    • pp.82-88
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    • 1997
  • This paper derives the generalized stiffness to find dynamic characteristics and its derivatives of a continuous system. And a new sensitivity analysis method is presented by using the amount of change of generalized stiffness and vibrational mode caused by the variation of stiffness. In this paper, to get or detect appropriate results, cantilever beam and stepped beam and stepped beam are used. Deviations of sensitivity coefficient, natural frequency, and vibrational mode are calculated as result, and compared with the theoretical exact values.

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Theoretical Study for the Characteristics of Melatonin (멜라토닌의 특성에 대한 이론적 연구)

  • Kim, Dong-Yeub;Jung, Maeng-Joon;Lee, Chul-Jae
    • Journal of the Korean Society of Industry Convergence
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    • v.15 no.2
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    • pp.59-63
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    • 2012
  • Melatonin has been studied as a potential treatment of cancer, immune disorders, cardiovascular diseases, depression, seasonal affective disorder (SAD), circadian rhythm sleep disorders, sexual dysfunction and some forms of insomnia. Prolonged release melatonin has shown good results in treating insomnia in older adults. It may ameliorate circadian misalignment and SAD. Basic research indicates that melatonin may play a significant role in modulating the effects of drugs of abuse such as cocaine. A 2004 review found that melatonin significantly increased total sleep time in people suffering from sleep restriction. Therefore, in this study, in order to explain characteristics of melatonin, total energy, net charge, vibrational mode of melatonin are calculated by PM3 methods of HyperCam 6.0.

Analysis of Natural Frequencies and Squeal Noise of KTX Brake Unit (KTX 제동장치의 고유진동수와 스퀼소음 분석)

  • Goo, ByeongChoon;Na, InKyun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.12
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    • pp.954-961
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    • 2014
  • Brake squeal noise of KTX is very uncomfortable to passengers and workers in stations. A lot of study has been conducted to inquire into the mechanism of the squeal noise. But understanding of the brake squeal noise is still challenging. In this study, we developed a full-scale tester equipped with a KTX mechanical brake unit. And we measured the vibrational characteristics of each component of the brake unit and compared them with frequency response functions of brake squeal noise measured also in the tester. It was found that the brake squeal noise was more closely related to the vibrational characteristics of the brake pads and hangers in friction condition than those of free components.

Theoretical Study for the Characteristics of Finasteride (피나스테라이드의 특성에 대한 이론적 연구)

  • Lee, Chul-Jae;Jung, Maeng-Joon;Kim, Dong-Yeub
    • Journal of the Korean Society of Industry Convergence
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    • v.16 no.3
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    • pp.69-74
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    • 2013
  • Finasteride, ($5{\alpha}$, $17{\beta}$)-N-(1,1-dimethylethyl)-3-oxo-4-azaandrost-1-ene-17-carboxamide), is a 5a-reductase enzyme inhibitor. This enzyme converts testosterone to the more potent androgen, a-dihydrotestosterone. This molecules a logical medical treatment for benign prostatic hyperplasia (BPH), as it induced a reduction in serum dihydrotestosterone and prostatic specific antigen levels with a concomittant increase in blood testosterone concentration . Despite its widespread use, little has been published concerning its molecular properties. Therefore, in this study, in order to explain characteristics of finasteride, total energy, net charge, vibrational mode of melatonin are calculated by PM3 methods of HyperCam 8.0.