• Title/Summary/Keyword: structural vibration

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Evaluation of Structural Integrity for HANARO Capsule Structure by Vibration Test and Analysis (진동시험 및 해석을 통한 하나로 캡슐 구조물의 구조건전성 평가)

  • 이영신;강연환;최명환;신도섭
    • Journal of KSNVE
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    • v.10 no.2
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    • pp.261-268
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    • 2000
  • The instrumented capsule is subjected to flow-induced vibration(FIV) due to the flow of the primary coolant and then the structural integrity of the capsule during irradiation in the HANARO reactor is an issue of major concern. For this purpose the acceleration was measured by four accelerometers attached to the protection tube of the capsule mainbody and the displacement of test holes was calcultated using commercial finite element program ANSYS to evaluate the structural interference with the neighboring flow tubes under the reactor operating condition. The calculated displacements of test holes in the reactor in-core were found to be lower than the values of allowable design criteria.

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The Analysis of Transmission Characteristics of Closed Structure with Internal Source Using FEM/BEM (유한.경계요소법을 이용한 내부음원을 갖는 닫힌 구조물의 차음 특성 해석)

  • Won, Sung-Gyu;Jung, Weui-Bong;Seo, Yeung-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.318-321
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    • 2005
  • In vibro-acoustic analysis, the commercial CAE tools, such as SYSNOISE, is usually used to take into account of the coupled effects of fluid acoustics and structural vibration. The acoustic field can be solved by either FEM or BEM, while the vibration field is usually solved by FEM. The interior or exterior acoustic problems with the coupled effects of the structural boundary could be solved by the commercial tools. The commercial tools, however, could not solve the problems in case that both the interior and exterior acoustic field is coupled with the structural boundary. In this paper, a realistic method based on FEM/BEM coupling scheme is presented to analyze the acoustic radiation from the internal source in a chamber to external acoustic field through elastic structural boundary. Several numerical examples are implemented to validate the developed program.

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Structural Vibration and Noise Characteristics of Pipe Structures (파이프 구조물의 구조진동 및 소음특성)

  • Ryu B.J.;Shin G.B.;Han H.H.;Lee G.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.1459-1462
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    • 2005
  • The paper deals with the structural vibration and noise characteristics of pipe structures. In general, A structure bone noise has a great effect on the drain noise of toilets, and depends on the natural frequency of the related structures. In order to measure and to find the relationships between structural vibration and noise of the pipe structures, some experiments have been performed. Through the experiments, impact acceleration signal in time domain and magnitude of transfer function in the frequency domain have been investigated for three kinds of pipes. Transmission loss of pipes depending on the frequency ranges was also found by using small speakers as a sound source.

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Dynamic Characteristics of a Damaged Plate

  • Lee, Usik
    • Journal of Mechanical Science and Technology
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    • v.15 no.10
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    • pp.1408-1416
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    • 2001
  • It is very important to well understand the dynamic characteristics of damaged structures to successfully develop or to choose a most appropriate structural damage identification method (SDIM) as the means of non-destructive testing. In this pope., the dynamic equation of motion for damaged plates is derived by introducing a damage distribution function, which may characterize the effective state of structural damages. It is found that structural damages may induce the coupling between modal coordinates. The effects of damages on the vibration characteristics of a plate depending on their locations, sizes, and magnitudes are numerically investigated in a systematic way. The numerical investigations are also given to the effects of damage-induced modal coupling on the changes in vibration characteristics and to the minimum number of natural modes required to predict sufficiently accurate vibration characteristics of damaged plates.

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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.

Efficient Super-element Structural Vibration Analyses of a Large Wind-turbine Rotor Blade Considering Rotational and Aerodynamic Load Effects (회전 및 풍하중 가진 효과를 고려한 대형 풍력발전 로터의 효율적인 슈퍼요소 구조진동해석)

  • Kim, Dong-Man;Kim, Dong-Hyun;Park, Kang-Kyun;Kim, Yu-Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.7
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    • pp.651-658
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    • 2009
  • In this study, computer applied engineering(CAE) techniques are fully used to efficiently conduct structural and dynamic analyses of a huge composite rotor blade using super-element. Computational fluid dynamics(CFD) is used to predict aerodynamic loads of the rotating wind-turbine blade. Structural vibration analysis is conducted based on the non-linear finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results are presented for comparison and the structural dynamic behaviors of the rotor blade are investigated herein.

Structural Intensity Analysis of Plate Structures Using Modal Analysis (모달해석기법을 이용한 판 구조물의 진동인텐시티 해석)

  • 정상민;조대승;김사수
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1998.04a
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    • pp.319-326
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    • 1998
  • Structural intensity of plates experiencing bending vibration is analytically evaluated using the modal analysis based on the assumed mode method. In the analysis, material internal loss and localized damping are considered. The power obtained by structural intensity integration over the circle containing the excitation source is compared with the power injected into plates to verify the accuracy of the presented method and; to evaluate the convergence of mode superposition. The intensity integration is carried out varying the circle radius and the integral step to investigate their effects in case of the power estimation using structural intensities. In addition, the dominant component among internal forces in the energy transfer by the bending vibration of a stiffened plate is investigated.

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Estimation of Structural Damage by Blasting Vibration Considering the Environmental Crack Deformation (일상 환경변화를 고려한 구조물 진동피해의 수준 평가)

  • 정지문;양형식
    • Journal of the Korean Geotechnical Society
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    • v.15 no.5
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    • pp.57-64
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    • 1999
  • In order to decide critical vibration level on structural damages induced by near blasting, deformation of existing cracks in structure was investigated and ground vibrations were measured. New criteria to evaluate blasting damage to structure are proposed considering daily deformation of cracks in structures. Results from 2 brick houses in fishing village show that new design criteria far more than current are required to cause structural damage for brick houses.

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Vibration reduction of military vehicle frame with using structural dynamic characteristics analysis (구조 동특성 분석을 통한 군용 차량 프레임 진동 저감)

  • Lee, Sang-Jeong;Park, Jong-Beom;Park, No-Cheol;Lee, Jong-Hak;Kim, Han-Shang;Jeong, Eui-Bong
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2014.10a
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    • pp.281-284
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    • 2014
  • Unlike ordinary vehicle chassis frame, chassis frame of military vehicle is long and that is operated in harsh driving environment in middle of war. Thus, because large dynamic loads is acting on the frame, it is important to secure the durability of the frame based on the structural dynamic characteristic analysis. The purpose of the study is that the chassis frame is optimized to secure durability of the chassis frame of the military vehicle according to the structural dynamic characteristic analysis. Also, structure optimization are performed using parametric optimization and topology optimization methods.

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Visualization of Sound Field of Plate-Cavity Coupled System by Experimental Method (실험적 방법에 의한 평판-공동 연성계의 음장 가시화)

  • 김시문;김양한
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1997.04a
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    • pp.662-668
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    • 1997
  • Since the structural impedance is much greater than that of medium in the most cases, we often assume that the structure is rigid and that the structural vibration is independent of medium, i.e. we usually calculate the vibration of the structure first, and then obtain the radiation sound from it. This assumption is no longer satisfied when the structural stiffness is small or the fluid impedance is comparable to it. This situation often happens in underwater acoustics. Although many researchers have studied about structural-fluid coupling, we have difficulties in solving the problem analytically. Therefore the numerical method using powerful computation leads us to obtain the various coupling problem. To understand the physical coupling phenomena, visualization of sound field by a geometrically simple system(plate-cavity coupled system) is performed experimentally. Acoustic holographic method is used to estimate sound field.

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