• 제목/요약/키워드: flexible deformation

검색결과 389건 처리시간 0.047초

연성이음관의 변형억제방안에 관한 수치모델연구(II): 콘크리트베딩 보강효과 (Numerical Model Study on a Scheme to Restrain Deformation of a Conduit with Flexible Joints(II) : Effectiveness of Concrete Bedding Reinforcement)

  • 손준익;정하익
    • 한국지반공학회지:지반
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    • 제7권4호
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    • pp.15-24
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    • 1991
  • 본 연구에서는 부등침하를 받는 매설관 연성이음부 하부의 베딩보강에 관한 적용성을 유한요소해 석을통하여 검토하였다. 매설관하부 기초지반에 설치된 콘크리트베딩의 강성 변화에 따른연성이 음부의 변형억제효과를 분석하였다. 지반부등침하가 발생하는 현장조건을 크게 세가지로 구분하였 으며 각 경계조건별로 베딩강성 변화에 따른 연성이음관의 변형형태를 살펴보았다. 해석결과는 보강과 비보강조건을 상호 비교 검토하여 콘크리트 베딩보강에 의한 연성이음관의 침하억제효과를 살펴보았다.

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모드 근사화 방법을 이용한 대변위 운동을 하는 유연구조물의 비선형 모델링 및 동적해석 (Nonlinear Modeling and Dynamic Analysis of Flexible Structures Undergoing Overall Motions Employing Mode Approximation Method)

  • 김정영;현상학;유홍희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2001년도 추계학술대회논문집A
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    • pp.550-555
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    • 2001
  • This paper presents a nonlinear modeling method for dynamic analysis of flexible structures undergoing overall motions that employs the mode approximation method. This method, different from the naive nonlinear method that approximates only Cartesian deformation variables, approximates not only deformation variables but also strain variables. Geometric constraint relations between the strain variables and the deformation variables are introduced and incorporated into the formulation. Two numerical examples are solved and the reliability and the accuracy of the proposed formulation are examined through the numerical study.

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4절 링크기구의 유연성 해석 (Flexibility Analysis of 4-Bar Linkage Mechanism)

  • 조선휘;박종근;한성현
    • 대한기계학회논문집
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    • 제18권6호
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    • pp.1365-1373
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    • 1994
  • Elasto-dynamic deformation of flexible linkage mechanism was analyzed using the finite element method. A computer program was constructed and applied to analyze a specific crank-level 4-bar mechanism, in which the elasto-dynamic deformation of the mechanism system was obtained using mode superposition method in the case of constant input speed and the effect of geometric stiffness on the mechanism is included. Experimental verification of numerical results was conducted by measuring the elasto-dynamic deformation of mid-points of coupler and lever for the 4-bar lingkage mechanism using high speed camera and image data processing systeem. For the elasto-dynamic deformation at the lever mid-point, the numerical results including geometric stiffness almost agree with the experimental ones. However, the numerical results excluding geometric stiffness good agree with the experimental ones at the couper mid-point.

상대 좌표를 이용한 종이류 모델링 기법 (Three-Dimensional Sheet Modeling Using Relative Coordinate)

  • 조희제;배대성
    • 대한기계학회논문집A
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    • 제29권2호
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    • pp.247-252
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

섬유다발의 굴곡도에 따른 유연직물복합재료의 등가탄성계수 예측 (Prediction of Equivalent Elastic Modulus for Flexible Textile Composites according to Waviness Ratio of Fiber Tows)

  • 서영욱;김성준;안석민
    • 항공우주기술
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    • 제9권2호
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    • pp.73-79
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    • 2010
  • 본 연구에서는 비선형 유한요소 해석을 수행하여 굴곡도에 따른 유연직물복합재료의 등가 탄성계수를 예측하였다. 해석은 상용 유한요소 해석 프로그램인 ABAQUS를 사용하여 수행되었다. 해석에서는 섬유다발의 재료적 비선형성과 대변형 시 발생하는 기하학적 비선형성이 고려되었으며, 섬유다발의 대 전단 변형으로 발생하는 기하학적 비선형성을 고려하기 위하여 사용자 부프로그램을 작성하여 이를 ABAQUS내에 삽입하였다. 결과에서는 일축하중 상태에 있는 유연직물복합재료의 응력-변형률 거동을 예측하여 이로부터 계산된 등가탄성계수를 시험결과와 비교하였으며, 다양한 섬유 굴곡도를 갖는 유연직물복합재료에 대한 등가탄성계수를 계산하였다.

Simulation and Experimental Methods for Media Transport System: Part I, Three-Dimensional Sheet Modeling Using Relative Coordinate

  • Cho, Heui-Je;Bae, Dea-Sung;Choi, Jin-Hwan;Lee, Soon-Geul;Rhim, Sung-Soo
    • Journal of Mechanical Science and Technology
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    • 제19권spc1호
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    • pp.305-311
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

상대좌표를 이용한 3차원 미디어 이송장치에 대한 실험방법과 Simulation에 대한 연구 (Simulation and Experimental Methods for Three-Dimensional Sheet Media Transport System Using Relative Coordinate)

  • 배대성;조희제
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 추계학술대회논문집
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    • pp.573-576
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    • 2005
  • This research presents a three-dimensional modeling technique for a flexible sheet. A relative coordinate formulation is used to represent the kinematics of the sheet. The three-dimensional flexible sheet is modeled by multi-rigid bodies interconnected by out-of-plane joints and plate force elements. A parent node is designated as a master body and is connected to the ground by a floating joint to cover the rigid motion of the flexible sheet in space. Since the in-plane deformation of a sheet such as a paper and a film is relatively small, compared to out-of-plane deformation, only the out-of-plane deformation is accounted for in this research. The recursive formulation has been adopted to solve the equations of motion efficiently. An example is presented to show the validity of the proposed method.

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Ground Deformation Evaluation during Vertical Shaft Construction through Digital Image Analysis

  • Woo, Sang-Kyun;Woo, Sang Inn;Kim, Joonyoung;Chu, Inyeop
    • KEPCO Journal on Electric Power and Energy
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    • 제7권2호
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    • pp.285-293
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    • 2021
  • The construction of underground structures such as power supply lines, communication lines, utility tunnels has significantly increased worldwide for improving urban aesthetics ensuring citizen safety, and efficient use of underground space. Those underground structures are usually constructed along with vertical cylindrical shafts to facilitate their construction and maintenance. When constructing a vertical shaft through the open-cut method, the walls are mostly designed to be flexible, allowing a certain level of displacement. The earth pressure applied to the flexible walls acts as an external force and its accurate estimation is essential for reasonable and economical structure design. The earth pressure applied to the flexible wall is closely interrelated to the displacement of the surrounding ground. This study simulated stepwise excavation for constructing a cylindrical vertical shaft through a centrifugal model experiment. One quadrant of the axisymmetric vertical shaft and the ground were modeled, and ground excavation was simulated by shrinking the vertical shaft. The deformation occurring on the entire ground during the excavation was continuously evaluated through digital image analysis. The digital image analysis evaluated complex ground deformation which varied with wall displacement, distance from the wall, and ground depth. When the ground deformation data accumulate through the method used in this study, they can be used for developing shaft wall models in future for analyzing the earth pressure acting on them.

분기기 궤도 유연체 모델링 및 동역학 해석 (Dynamic Analysis for a Flexible Track Modeling of Turnout)

  • 김만철;황성호;황광하;현상학
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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    • pp.2830-2837
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    • 2011
  • In this paper, a flexible track modeling of turnout was developed and dynamic characteristics of turnout rails were analyzed when a vehicle passed through the turnout. The flexible track modeling is effective to the stiffness and durability design of turnout, because it can capture the deformation and dynamic stress due to the collision of between wheels and rails when the vehicle move to the tongue rail. Also, a more accurate running safety can be obtained by considering the interaction between wheel and rail deformation. Solid finite elements were used for variable cross-sections of rails and the variation of rubber stiffness was modeled. The proposed flexible track modeling in this paper was verified to be valid by comparison with the experiment of the turnout system.

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DADS 및 MSC/NASTRAN을 이용한 다물체계 유연물체의 동역학 해석

  • 김창부;백윤기
    • 한국정밀공학회지
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    • 제18권2호
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    • pp.63-71
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    • 2001
  • This paper introduces a method for calculation of dynamic stress occurring in flexible bodies of a moving multibody system by using commercial softwares DADS for dynamic analysis and MSC/NASTRAN for finite element analysis. Three methods for model transient response analysis of a flexible body are summarized. Elastic deformation of a flexible body can be described with normal modes and static modes composed of constraint modes and residual attachment modes. The deformation modes divided into fixed-interface modes and free-interface modes can be determined by using MSC/NASTRAN and selected for dynamic analysis. The dynamic results obtained from DADS are utilized to calculate dynamic stress by using mode-displacement method or mode-acceleration method of MSC/NASTRAN. As a numerical example of the analysis, we used a three dimensional slider-crank model with a flexible connecting rod.

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