• 제목/요약/키워드: force vibration

검색결과 2,594건 처리시간 0.033초

Investigation on vortex-induced vibration of a suspension bridge using section and full aeroelastic wind tunnel tests

  • Sun, Yanguo;Li, Mingshui;Liao, Haili
    • Wind and Structures
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    • 제17권6호
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    • pp.565-587
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    • 2013
  • Obvious vortex induced vibration (VIV) was observed during section model wind tunnel tests for a single main cable suspension bridge. An optimized section configuration was found for mitigating excessive amplitude of vibration which is much larger than the one prescribed by Chinese code. In order to verify the maximum amplitude of VIV for optimized girder, a full bridge aeroelastic model wind tunnel test was carried out. The differences between section and full aeroelastic model testing results were discussed. The maximum amplitude derived from section model tests was first interpreted into prototype with a linear VIV approach by considering partial or imperfect correlation of vortex-induced aerodynamic force along span based on Scanlan's semi-empirical linear model. A good consistency between section model and full bridge model was found only by considering the correlation of vortex-induced force along span.

자전거용 반능동 현가기구 개발에 관한 연구 (The study on the semi-active suspension system for bicycle)

  • 주형준;김찬중;이동원;이봉현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2011년도 추계학술대회 논문집
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    • pp.775-780
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    • 2011
  • This paper represents the study on the development of semi-active bicycle suspension system. The road vibration and transmissibility of front suspension are obtained by driving test on proving ground. The numerical simulation is evaluated by dynamic system modeling and equation of motion. The numerical simulation are performed to estimate the optimal damping force for minimal vibration transmission. And oscillating displacement is calculated and analyzed. Therefore the stoke which convert the damping characteristics is suggested from the driving test and numerical simulation.

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선삭가공에 있어서 채터진동의 인프로세스 검출에 관한 연구 (I) (A Study on In-Process Detection of Chatter Vibration in a Turning Process)

  • 구연욱;정의식;남궁석
    • 한국정밀공학회지
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    • 제8권3호
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    • pp.73-81
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    • 1991
  • There have been many studies on chatter vibration in machining but there seems to be no regulations to decide the commencing point of chatter objectively. The development of an objective method which can estimate and detect chatter commencement is very much in need for automatic manufacturing systems, dynamic performance tests for machine tools, so on. In this study, therefore, the estimation and the in-process detection of chatter have been experi- mentally investigated for the turning process. As a result, the commencing point of chatter can be decided from the behavior of the maximum amplitude of the dynamic component of cutting force, where the maximum amplitude is suddenly increasing with the chatter commencement. Then the commencing point of chatter can be estimated practically by this method before the occurrence of excessive vibration. Also, it is possible to detect the occurence of chatter vibration through the in-process measurement, by monitoring the maximum amplitude of the dynamic component of cutting force.

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발전기 고정자의 진동특성을 위한 전처리기 프로그래밍 (Pre-processor programing for the vibrational characteristic of generator's stator)

  • 안창기;배용채;함지웅;이동원
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2012년도 추계학술대회 논문집
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    • pp.476-481
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    • 2012
  • A plant's generator system under operating condition has been suffered the vibration from the excitation force with 120Hz. The vibration is generated in the stator end windings. For analyze dynamic characteristics of the generator's stator, its finite element model were obtained using ANSYS software package for modal and harmonic analysis. we compare the analysis result with experimental data. The results show that the resonance frequency, which is related with second ecliptical mode on the stator end windings 129Hz. The experimental results are good agreement with the FEA model.

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적합직교분해법을 이용한 AFM 마이크로캔틸레버의 진동해석 (Vibration Analysis of the Tapping AFM Microcantilevers Using Proper Orthogonal Decomposition)

  • 홍상혁;이수일
    • 한국소음진동공학회논문집
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    • 제20권4호
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    • pp.414-421
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    • 2010
  • The proper orthogonal decomposition(POD) is used to the vibration analysis of microcantilever in tapping mode atomic force microscopy(AFM). The proper orthogonal modes (POM) are extracted from vibrating signals of microcantilever when it resonates and taps the sample. We present recent ideas based on POD and detailed experiments that yield new perspectives into the microscale structures such as the tapping cantilever. The linearized modeling technique based on POD is very useful to show the principal characteristics of the complex dynamic responses of the AFM microcantilever.

A Strategy for Moving Mass Systems from One Point to Another without Inducing Residual Vibration

  • Yoon, Byung-Ok;Karnopp, Bruce-H.
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 1993년도 추계학술대회논문집; 반도아카데미, 26 Nov. 1993
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    • pp.29-34
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    • 1993
  • In many circumstances, it is desired to move a mass from one position to another without inducing any vibration in the mass being moved. Two such problems are considered here: the motion of a pendulum initiated by the specified motion of its support. In each case, it is desired that the system start at rest and come to rest in the second position. A simple strategy for the specified motion is given here. The method is motivated by engine cam-follower design. The force required to move the system in question is determined as well as the maximum value of the force required (and the times at which these forces take place) is determined.

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Optically Actuated Carbon Nanocoils

  • Wang, Peng;Pan, Lujun;Li, Chengwei;Zheng, Jia
    • Nano
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    • 제13권10호
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    • pp.1850112.1-1850112.6
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    • 2018
  • Optical manipulation on microscale and nanoscale structures opens up new possibilities for assembly and control of microelectromechanical systems and nanoelectromechanical systems. Static optical force induces constant displacement while changing optical force stimulates vibration of a microcantilever/nanocantilever. The vibratory behavior of a single carbon nanocoil cantilever under optical actuation is investigated. A fitting formula to describe the laser-induced vibration characteristics is deduced based on a classical continuum model, by which the resonance frequency of the carbon nanocoil can be determined directly and accurately. This optically actuated vibration method could be widely used in stimulating quasi-1D micro/nanorod-like materials, and has potential applications in micro-/nano-opto-electromechanical systems.