• Title/Summary/Keyword: structural vibration

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A Study on Vibration Analysis Method Using the Global Structural Analysis Model (전선 구조해석 모델을 이용한 진동해석 방법에 관한 연구)

  • Park, Hyung-Sik;Choi, Su-Hyun;Lee, Yong-Sub
    • Journal of the Society of Naval Architects of Korea
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    • v.44 no.3 s.153
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    • pp.314-322
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    • 2007
  • In general, the vibration and structural analyses have been carried out by using each finite element model separately because of different size of finite element mesh and different focusing area of each analysis. In some cases, however, it is required to perform both global vibration and structural analyses at the same time using a finite element model for global structural analysis, which asks for a special treatment for a vibration analysis. In this study, a technique to perform a global vibration analysis using a finite element model for a global structural analysis has been developed and its effectiveness has been verified by its application to a whole ship.

Measurements on the Characteristics of Dynamic and Vertical Vibration Transfer according to floors of Building Structures using Accelerometer and Dynamic signal analyzer (가속도계와 동적신호분석기를 이용한 건축물 바닥슬래브 동특성 및 수직진동 전달특성 측정)

  • Chun Ho-Min
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.29-34
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    • 2006
  • In general, the vertical vibration problems for .strength of members and serviceability of building structures are not considered in structural design process, but the prediction of the vertical vibration is very important and essential to structural design process. This study aims to investigate the characteristics of vertical vibration in terms of the transfer of horizontal directions on the rahmen building structures. In order to examine the characteristics of vertical vibration, the modal test and the impact (heel-drop and hammer) excitation experiments were conducted several times on three building structures. The results from the experiments are analyzed and compared. with the results. The results of this study suggest that the characteristics of vertical vibration transfer in horizontal way are effected from the fundamental frequency of the slabs and excitation forces.

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Transverse vibration reduction at navigation bridge deck of the shuttle tanker using structural intensity analysis (진동 인텐시티 해석을 통한 원유운반선의 거주구 횡방향 진동 저감 연구)

  • Kim, Ki-Sun;Kim, Heui-Won;Joo, Won-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.10a
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    • pp.251-255
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    • 2012
  • Structural intensity has been mainly utilized to identify vibration energy flow in a vessel. In this paper, the structural intensity of a shuttle tanker subjected to H-moment of the main engine was calculated using a finite element model. From the analysis, it was found that the top-bracing elements, which support the main engine onto the hull structure to prevent the excessive transverse vibration of the main engine, play the role of the dominant path and sink for vibration energy flow from the main engine. Therefore, the structural intensity was controlled by the modification of stiffness and damping characteristics of the top-bracing elements. As a result, it is observed that the transverse vibration level at the center of navigation bridge deck decreased after the control of structural intensity.

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Vertical Z-vibration prediction model of ground building induced by subway operation

  • Zhou, Binghua;Xue, Yiguo;Zhang, Jun;Zhang, Dunfu;Huang, Jian;Qiu, Daohong;Yang, Lin;Zhang, Kai;Cui, Jiuhua
    • Geomechanics and Engineering
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    • v.30 no.3
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    • pp.273-280
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    • 2022
  • A certain amount of random vibration excitation to subway track is caused by subway operation. This excitation is transmitted through track foundation, tunnel, soil medium, and ground building to the ground and ground structure, causing vibration. The vibration affects ground building. In this study, the results of ANSYS numerical simulation was used to establish back-propagation (BP) neural network model. Moreover, a back-propagation neural network model consisting of five input neurons, one hidden layer, 11 hidden-layer neurons, and three output neurons was used to analyze and calculate the vertical Z-vibration level of New Capital's ground buildings of Qingdao Metro phase I Project (Line M3). The Z-vibration level under different working conditions was calculated from monolithic roadbed, steel-spring floating slab roadbed, and rubber-pad floating slab roadbed under the working condition of center point of 0-100 m. The steel-spring floating slab roadbed was used in the New Capital area to monitor the subway operation vibration in this area. Comparing the monitoring and prediction results, it was found that the prediction results have a good linear relationship with lower error. The research results have good reference and guiding significance for predicting vibration caused by subway operation.

Vibration and Stress Analysis for Reactor Vessel Internals of Advanced Power Reactor 1400 by Pulsation of Reactor Coolant Pump (원자로냉각재펌프 맥동에 대한 APR1400 원자로내부구조물의 진동 및 응력 해석)

  • Kim, Kyu-Hyung;Ko, Do-Young;Kim, Sung-Hwan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.21 no.12
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    • pp.1098-1103
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    • 2011
  • The structural integrity of APR1400 reactor vessel internals has been being assessed referring the US Nuclear Regulatory Commission regulatory guide 1.20, comprehensive vibration assessment program. The program is composed of a vibration and stress analysis, a vibration and stress measurement, and an inspection. This paper covers the vibration and stress analysis on the reactor vessel internals by the pulsation of reactor coolant pump. 3-dimensional models to calculate the hydraulic loads and structural responses were built and the pressure distributions and the structural responses were predicted using ANSYS. This paper presents that APR1400 reactor vessel internals have enough structural integrity against the pulsation of reactor coolant pump as the peak stress of the reactor vessel internals is much lower than the acceptance limit.

Evaluation of Diesel Engine Structural Vibration Using Phase Vector Sum (Phase vector sum을 이용한 디젤엔진 구조진동의 평가)

  • 이수목;김관영
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.383-388
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    • 2003
  • As an effective way of response evaluation in structural vibration analysis, the phase vector sum(PVS) method used in shaft torsional vibration analysis is introduced. Basic relation of PVS applicable to structural problem is derived and applied to Diesel engine structures. Concepts of forced phase vector sum (FPVS) and significance level (SL) are proposed to visualize the correlation between excitation orders and vibration modes in the SL map. The maximum responses and SL are compared and reviewed to confirm the validity of the method. It is regarded FPVS is adequate to newly evaluate the structural vibration based on excitation information.

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Vibration Reduction Effect and Structural Behavior Analysis for Column Member Reinforced with Vibration Non-transmissible Material (진동절연재로 보강된 기둥부재의 진동저감효과 및 구조적 거동분석)

  • Kim, Jin-Ho;Yi, Na-Hyun;Hur, Jin-Ho;Kim, Hee-Kyu
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.4
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    • pp.94-103
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    • 2016
  • For elevated railway station on which track is connected with superstructure of station, structural vibration level and structure-borne-noise level has exceeded the reference level due to structural characteristics which transmits vibration directly. Therefore, existing elevated railway station is in need of economical and effective vibration reduction method which enable train service without interruption. In this study, structural vibration non-transmissible system which is applied to vibroisolating material for column member is developed to reduce vibration. That system is cut covering material of the column section using water-jet method and is installed with vibroisolating material on cut section. To verify vibration reduction effect and structural performance for structural vibration non-transmissible system, impact hammer test and cyclic lateral load test are performed for 1/4 scale test specimens. It is observed that natural period which means vibration response characteristics is shifted, and damping ratio is increased about 15~30% which means that system is effective to reduce structural vibration through vibration test. Also load-displacement relation and stiffness change rate of the columns are examined, and it is shown that ductility and energy dissipation capacity is increased. From test results, it is found that vibration non-transmissible system which is applied to column member enable to maintains structural function.

A Study on Structural Intensity Measurement of 2-dimensional Structure (2차원 구조물의 진동 인텐시티 계측에 대한 연구)

  • 이덕영;박성태
    • Journal of KSNVE
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    • v.7 no.3
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    • pp.477-488
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    • 1997
  • In order to control vibration in structures, it is desirable to be able to identify dominant paths of vibration transmission from sources through the structure to some points of interest. Structural intensity vector(power flow per width of cross section) using cross spectra is able to measure the vibration power flow at a point in a structure. This paper describes the structural intensity measurement of 2-dimensional structure. Structural intensity of 2-dimensional structure can be obtained from eight point cross spectral measurement per axis, or two point measurement per axis on the assumption of far field. Approximate formulation of the relation between bending waves in structures and structural intensity makes it possible to separate the wave components by which one can get a state of the vibration field. Experimental results are obtained on an infinite plate at the near and far field in flexural vibration. The measurement error of two point measurement is rather bigger than eight point measurement on account of the assumption that Poisson's ratio is 1. The structural intensity vectors on the plate are checked the ability to identify the path of vibration power flow in random excitation and 200Hz sine excitation, the result of two point measurememt is almost the same as the result of eight point measurement in 200Hz sine excitation.

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Study on Sound Transmission through a Panel including Structural Vibration (구조 진동을 고려한 평판 구조물 음향 투과 특성 연구)

  • Chang, Woo-Suk;Kim, Won-Cheol
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.811-816
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    • 2011
  • This study includes investigation on sound transmission phenomena through a structural panel including structural vibration and feedback control methodology to minimize the transmission. Focus is placed on finding the relation between vibration pattern and sound transmission, and on finding optimal sensor and actuator location. A simple analog feedback control circuit is designed and implemented to verify the approach.

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Flow-Induced Vibration Characteristics of a Missile Control Surface Considering Shock Wave and Structural Nonlinearity (충격파 및 구조비선형성을 고려한 미사일 조종면의 유체유발 진동특성)

  • Kim, Dong-Hyun;Lee, In;Kim, Seung-Ho
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.389.2-389
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    • 2002
  • Nonlinear aeroelastic characteristics of a missile control surface are investigated in this study. The wing model has freeplay structural nonlinearity at its pitch axis. Nonlinear aerodynamic flows with unsteady shock waves are also considered in high-speed flow region. To effectively consider a freeplay structural nonlinearity, the fictitious mass method (FMM) is applied to structural vibration analysis based on finite element method (FEM). (omitted)

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