• 제목/요약/키워드: structural change

검색결과 3,363건 처리시간 0.038초

동특성변화에 따른 구조물의 변경된 설계파라미터 예측 (Prediction of Structural Modified Design Parameter due to the Change of Dynamic Characteristic)

  • 이정윤
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2004년도 춘계학술대회 논문집
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    • pp.191-196
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    • 2004
  • This study proposed the analysis of mass position detection and modified stiffness due to the change of the mass and stiffness of structure by using the original and modified dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom by modifying the mass. The predicted detection of mass positions and magnitudes are in good agrement with these from the structural reanalysis using the modified mass.

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건전도 모니터링을 위한 P.C. 상자형 교량의 동적 특성 분석 (A Study on Dynamic Characteristics of P.C. Box Girder Bridge for Condition Monitoring)

  • 이선구;이성우
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1996년도 가을 학술발표회 논문집
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    • pp.131-137
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    • 1996
  • To perform condition monitoring of P.C. Box girder bridge under ambient traffic, dynamic characteristics were identified using the results of load test an analysis. It was found that natural frequencies obtained from the measured acceleration data for the forced vibration part and free vibration part were nearly identical. Thus it can be concluded that dynamic parameters are properly determined under ambient traffic condition. Finite element model for analysis was calibrated using measured frequencies. Change of dynamic characteristics were predicted through analysis of the established finite element model with anticipated change.

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동특성 변화를 이용한 구조물의 손상 탐지 해석 (Analysis of a Structural Damage Detection using the Change of Dynamic Characteristics)

  • 이정윤;이정우;이준호
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2003년도 춘계학술대회 논문집
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    • pp.760-763
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    • 2003
  • This study proposed the analysis of damage defection due to the change of the stiffness of structure by using the original and modified dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom by modifying the stiffness. The predicted damage detections are in good agreement with these from the structural reanalysis using the modified stiffness.

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동특성 변화로부터 구조물의 변경질량 위치 해석 (Analysis of Mass Position Detection Using the Change of the Structural Dynamic Characteristics)

  • 이정윤
    • 한국공작기계학회논문집
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    • 제13권2호
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    • pp.120-126
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    • 2004
  • This study proposed the analysis of mass position detection due to the change of the mass and strifeless of structure by using the original and modified dynamic characteristics. The method is applied to examples of the cantilevers beam and the 3 degrees of freedom system by modifying the mass. The predicted detection of the mass positions and magnitudes are in good agrement with the present study from the structural reanalysis using the modified mass.

접합부 강성변화를 고려한 단층 래티스 돔의 좌굴해석 (Buckling Analysis for Single Layer Latticed Domes considering the Change of Joint Rigidity)

  • 이후진;권택진
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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    • pp.337-344
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    • 2001
  • This paper is concerned with the change of joint rigidity in estimating the degree of semi-rigidity of connections and the buckling load in a single layer latticed dome. The estimations are based on information about the ratio for the rotational stiffness of the connection to the flexural stiffness of the member and the minimum eigenvalue of a structure for pinned, semi-rigid and completely rigid cases, respectively. Connection characteristics are reflected in the ratio control of joint rigidity for the DOFs to be related using the spring element by FEM.

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CSL 모델을 이용한 초기재령 콘크리트 거동 해석 (Modeling of Early Age Concretes Using a CSL Model)

  • 지광습;정진규
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2007년도 정기 학술대회 논문집
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    • pp.411-414
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    • 2007
  • The confinement-shear lattice(CSL) model for hardened concretes developed by Cusatis is extended for early age concretes. The uniaxial behaviors available in the literature for 3 to 28 days were simulated by the CSL model to identify the change of the model parameters for various ages. The change with respect to the age was interpolated based on the chemomechanics to develop the extended version of CSL model.

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동특성 변화로부터 구조물의 변경질량 위치 해석 (Analysis of detection of mass position using the change of the structural dynamic characteristics)

  • 이정윤
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 추계학술대회 논문집
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    • pp.209-213
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    • 2002
  • This study proposed the analysis of mass position detection due to the change of the mass and stiffness of structure by using the original and modified dynamic characteristics. The method is applied to examples of a cantilever and 3 degree of freedom by modifying the mass. The predicted detection of mass positions and magnitudes are in good agreement with these from the structural reanalysis using the modified mass.

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선반용 급속 교환 파워 척의 구조해석 및 성능평가 (Structural Analysis and Performance Evaluation of Quick Change Power Chuck for Lathe Operations)

  • 유중학
    • 한국생산제조학회지
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    • 제8권5호
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    • pp.90-95
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    • 1999
  • Chucking for workpieces is very important for productivity and efficiency in lathe operations. In point of productivity top jaws of the chuck should be changed as quickly as possible in order to reduce idle times wherever workpieces are regripped. A quick change power chuck which can change top jaws quickly by using a jaw change handle without any assembly/disassembly processes of screws is analyzed for this study. strength and stiffness of top jaws by centrifugal force are considered for the design. Structural analysis for the chuck is executed and the finite element method is introduced using MSC/NASTRAN software. Also, the performance of the chuck is evaluated by experiments.

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NMR Characterization of Oxidized Form of Human 8-kDa Dynein Light Chain

  • Shin, Jae-Sun;Jeong, Woo-Jin;Chi, Seung-Wook
    • 한국자기공명학회논문지
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    • 제14권2호
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    • pp.127-133
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    • 2010
  • Redox-dependent conformational change of human 8-kDa Dynein light chain (LC8) plays important role in regulating NF-${\kappa}B$ signaling pathway. In this study we characterized the structural states of the oxidized and reduced forms of LC8 by using NMR spectroscopy. The $^1H-^{15}N$ 2D HSQC spectra of oxidized LC8 indicated that no significant change in tertiary structure of LC8 occurred upon oxidation. The chemical shift perturbations of LC8 upon oxidation suggest a redox-dependent quaternary structural change.

신체의 Stiffened Plate 구조물의 모우드해석과 최적변경법에 관한 연구 (Study on the Optimum Modification and Modal Analysis of Stiffened Plate of Ship Hull Structure)

  • 박성현;박석주;고재용
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2000년도 제 25회 정기총회 및 추계학술발표회
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    • pp.51-58
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    • 2000
  • The purpose of this study is the optimum modification of dynamic characteristics of stiffened plate structure. In the method of the optimization ,finite element method (FEM), sensitivity analysis and optimum structural modification method are used. To begin with, using FEM, the dynamic characteristics of stiffened plate structure is analyzed. Next, rate of change of dynamic characteristic by the change of design variable is calculated using the sensitivity analysis. Then, amount of change of design variable is calculated using this sensitivity value and optimum structural modification method. The change of natural frequency is made to be an objective function. Thickness of plate and cross section moment become a design variable. It is shown that the results are effective in the optimum modification for dynamic characteristics of the stiffened plate structure.

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