• 제목/요약/키워드: Structural modification

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Characteristics of Near Field Earthquakes and its effect on Seismic demands (Near Field 지진의 특징과 구조응답에 대한 영향)

  • 배미혜;권오성;한상환
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2002.04a
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    • pp.208-213
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    • 2002
  • Near field ground motions contain distinct, large amplitude pulses in both velocity and displacement. This paper presents an investigation on the characteristics of near filed earthquakes and their effects on seismic demands. For this purpose 20 sets of near field ground motion and 20 sets of far filed ground motion are compared with respect to Linear Elastic Response Spectrum(LERS), Response Modification Factor(R), Inelastic Response Spectrum(IRS), and performance point of Capacity Spectum Method(CSM).

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Structural Vibration Characteristics for an Outdoor Units Support of an Air-conditioner (에어컨 실외기 받침대의 구조진동 특성)

  • Ryu, Bong-Jo;Song, Seon-Ho;Lim, Chae-Wook
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.11a
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    • pp.215-217
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    • 2008
  • This paper deals with the structural vibration characteristics for an outdoor units support of an air-conditioner. Even though main noise sources are compressor noise and fluid noise which is caused by the fan, the structural modification of the outdoor units support may affect vibration and noise. In this paper, damping ratios for two kinds of an outdoor units support of an air-conditioner are measured through the modal testing. In order to reduce the structural borne noise due to an outdoor units support of an air-conditioner, four kinds of rubber materials are selected and tested.

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Strength Evaluation of the Cylinder Cover Stud for Low-Speed Marine Diesel Engine (대형엔진 실린더 커버 스터드의 강도 평가)

  • Kim, Byung-Joo;Lee, Jae-Ock;Park, Jin-Soo;Kim, Se-Lak
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.554-559
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    • 2007
  • The cylinder cover stud for assembling the combustion chamber components of low-speed marine diesel engine is one of the main structural components in engine. To understand the structural behavior of the stud is quite important for safe and economic design of it. In this paper, the structural behavior and design adequacy of the stud have been evaluated through strain measurement and structural analysis for the world's two largest engine types. Moreover, a feasibility study for design modification was carried out based on fatigue test and calculation. The results showed that 1) the stud experiences very high stress ratio under normal operating conditions, 2) the fatigue strength of the stud is sufficient, and 3) results from strain measurement and structural analysis were quite close each other.

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Structural Optimization by Global-Local Approximations Structural Reanalysis based on Substructuring (부구조화 기반 전역-부분 근사화 구조재해석에 의한 구조최적화)

  • 김태봉;서상구;김창운
    • Journal of the Korean Society of Safety
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    • v.12 no.3
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    • pp.120-131
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    • 1997
  • This paper presents an approximate reanalysis methods of structures based on substructuring for an effective optimization of large-scale structural systems. In most optimal design procedures the analysis of the structure must be repeated many times. In particular, one of the main obstacles in the optimization of structural systems are involved high computational cost and expended long time in the optimization of large-scale structures. The purpose of this paper is to evaluate efficiently the structural behavior of new designs using information from previous ones, without solving basic equations for successive modification in the optimal design. The proposed reanalysis procedure is combined Taylor series expansions which is a local approximation and reduced basis method which is a global approximation based on substructuring. This technique is to choose each of the terms of Taylor series expansions as the basis vector of reduced basis method in substructuring system which is one of the most effective analysis of large -scale structures. Several numerical examples illustrate the effectiveness of the solution process.

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A Study on the Reduction of Booming Noise of an Automobile (승용차의 부밍 소음 저감에 관한 연구)

  • 이상현;강상욱;최형길;이장무;성명호
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1996.11a
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    • pp.867-871
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    • 1996
  • Recently many studies have been carried out to predict the characteristics of vehicle noise and to reduce the noise for enhancing the ride quality. In this study, the structural-acoustic coupling theory and the acoustic finite element theory were reviewed, and the structural acoustic coupling analysis was applied to an automobile. Because of nonuniformed lateral shape of a compartment cavity, the acoustic modes were calculated with 3-D finite element modeling. The structural modes were measured with the modal testing. Using the structural-acoustic cooling analysis, the modes which strongly coupled to the interior noise were identified and the boundary regions which could reduce noise level efficiently by structural modification were predicted.

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Study on Structural Design of Glass/epoxy Composite Blade and Tower of Vertical Axis Wind Turbine System (수직축 풍력 발전 시스템의 유리/에폭시 복합재 블레이드 및 타워 구조 설계 연구)

  • Park, Hyunbum
    • Composites Research
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    • v.31 no.3
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    • pp.104-110
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    • 2018
  • This study is to propose the structural design and analysis procedure about composite blade and tower of vertical axis wind turbine technology. In this study, structural design of tower for vertical axis wind turbine was performed after vertical blade design and manufacturing. The structural design requirement and specification of blade and tower was investigated. After tower of structural design, the structural analysis of the tower was conducted by the finite element method. It was performed that the stress, deformation and natural frequency analysis at the applied loading. The design modification of tower configuration was proposed by structural analysis. It was confirmed that the final designed tower structure is safety through the structural analysis.