• Title/Summary/Keyword: 應力經路

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Sediment Transport Paths of the East China Sea (동지나해(東支那海)의 토사이동경로(土砂移動經路))

  • Choi, Byung Ho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.3 no.4
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    • pp.83-93
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    • 1983
  • A non-linear numerical tidal model of the Yellow Sea and the East China Sea is used to derive the mean and maximum bed stress the mean and maximum transport potential on the continental shelf. It has provided a preliminary assessment of relation between sediment transport paths and the mean and maximum bed stress distribution determined from the numerical model.

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Prediction of Crack Propagation Path Using Boundary Element Method in IC Packages (반도체 패키지의 경계요소법에 의한 균열진전경로의 예측)

  • Chung, Nam-Yong
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.3
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    • pp.15-22
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    • 2008
  • Applications of bonded dissimilar materials such as integrated circuit(IC) packages, ceramics/metal and resin/metal bonded joints, are very increasing in various industry fields. It is very important to analyze the thermal stress and stress singularity at interface edge in bonded joints of dissimilar materials. In order to investigate the IC package crack propagating from the edge of die pad and resin, the fracture parameters of bonded dissimilar materials and material properties are obtained. In this paper, the thermal stress and its singularity index for the IC package were analyzed using 2-dimensional elastic boundary element method(BEM). From these results, crack propagation direction and path by thermal stress in the IC package were numerically simulated with boundary element method.

Application of p-Version Crack Model Based on J-integral Method in LEFM Analysis (선형탄성 파괴역학해석에서 J-적분법에 의한 p-Version 균열모델의 적용)

  • 이채규;우광성;김영인
    • Computational Structural Engineering
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    • v.8 no.4
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    • pp.137-148
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    • 1995
  • A new path independent contour integral formulus for the distinct calculation of mode I stress intensity factors in two dimensional linear elastic fracture mechanics problems is presented. This method is based on p-convergence concepts and can be easily appended to existing finite element computer codes. In this study, the stress state at crack tip has been investigated and the path independence of J-integral values has been tested with respect to different contours expressed by normalized distance apart from the crack tip. Numerical results by p-convergence for the problems such as centrally cracked panels, single and double edged cracks in rectangular panels have been compared with those by the conventional h-convergence. The comparison demonstrates the accuracy and stability of the proposed method.

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The Effects of Principal Stress Rotation in K0-Consolidated Clay (K0-압밀점토(壓密粘土)의 주응력회전(主應力回轉) 효과(効果))

  • Hong, Won Pyo
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.8 no.1
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    • pp.159-164
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    • 1988
  • The directions of the principal strain increment, stress, and stress increment during rotation of the principal stress axes at any stress level was studied for $K_0$-consolidated clay using torsion shear apparatus with individual control of the vertical stress, the confining pressure, and the shear stress on hollow cylinder specimens under undrained and drained condition. The torsion shear tests were performed according to predetermined stress-paths, which were chosen to cover over the full range of rotation of principal stress axes. The test results indicated that the strain increment vectors at failure coincided with the stress vectors. That is, the direction of strain increment coincided with the direction of stress increment at small stress levels and with the direction of stress at higher stress levels, which indicated that the behavior of clay was transfered from elastic to plastic as the stress level was increased. The applicability of the elastoplastic theory for modeling of the behavior of clay during rotation of the principal stress axes was given.

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Behavior of the Ground in Rectangularly Crossed Area due to Tunnel Excavation under the Existing Tunnel (II) (기존터널에 근접한 직각교차 하부터널의 굴착에 따른 교차부지반의 거동 (II))

  • Kim, Dong-Gab;Lee, Sang-Duk
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.7 no.2
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    • pp.133-141
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    • 2005
  • The behavior of the ground in crossed zone due to the excavation of new lower tunnel rectangularly crossed to that was studied by model tests and numerical analysis in shallow cover. Results of the model tests show that earth pressure of the ground in crossed zone were redistributed due to the longitudinal arching effect by the excavation of lower tunnel. By the numerical analysis, minimum principal stress in crown of single tunnel has more decrease than parallel tunnel or crossed tunnel. Vertical stress at rectangularly crossed tunnel decrease more than single tunnel by stress shadow.

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Strength Experimental Study on Precast Column-R.C. Foundation Anchor Joint Subjected to Cyclic Horizontal Loading (반복-수평력을 받는 프리캐스트기둥- RC기초 Anchor 접합부의 내력 실험 연구)

  • Lee, Ho;Jung, Hwoan-Mok;Cha, Byung-Gi;Byun, Sang-Min
    • Journal of Korean Association for Spatial Structures
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    • v.9 no.2
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    • pp.45-52
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    • 2009
  • This paper experimentally evaluates the strength characteristics of precast column-R.C. foundation anchor joint subjected to the cyclic horizontal load. The study presents differences in accurate stress transfer path and destruction mechanism between the concrete structural body applying the precast column-R.C. foundation anchor joint and the concrete structural body applying the steel joint. the result from width load experiment on reinforcing steel under the cyclic horizontal load provides the necessary minimum insertion length to construct the precast column-R.C. foundation anchor joint. This study also presents the accurate stress transfer path and destruction mechanism on the anchor joint th meet the customer's requirements, comparing stress transfer path and destruction mechanism provided by the experiment and those provided by the product manual. Eventually, this study presents all the necessary fundamental data to provide the construction design with accurate number of reinforcing steel, diameter of the steel, fixation length of the steel, etc. to build the optimum precast concrete column.

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The Computation of Stress Intensity Factors in Fiberreinforced Composites using a Contour Integral Method (경로적분법에 의한 섬유강화복합재의 응력확대계수 계산)

  • 김진우;장흥석
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.9 no.1
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    • pp.109-118
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    • 1985
  • 특이응력해석을 위한 일반화된 가역상반일 경계분식이 섬유강화복합재를 모형화한 직교 이방성 크랙평판의 수치해를 위하여 발전시켰다. 이 적분방정식은 평판경계에서의 탄성변위와 트랙션의 변수로 구성된 경계분식의 형태로 하중이 없다는 두 크랙면의 경계조건과 유한의 탄성변형에너지 의 개념에서 경계적 분식에 필요한 특성해를 규정하고 대응되는 보조해를 계산하였다. 직교이방 도를 달리한 중앙크랙평판의 응력확대계수를 계산하여 기존해와 비교하였다. 또한 대칭모우드 I 형의 양측크랙평판 및 복합모우드형 편측크랙 일단고정 평판의 응력확대계수가 임의의 섬유방향 각에 따라서 계산되었다.

플로팅 구조물 주각부의 유한요소 해석

  • Song, Hwa-Cheol;Kim, Se-Cheol
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.10a
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    • pp.282-284
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    • 2012
  • 해양플랜트의 관심의 증가로 사업의 수요가 많아지고 플랜트 사업이 활발해지고 있다. 플로팅구조물의 상부구조물과 하부구조물간의 발생 할 수 있는 집중응력으로 인한 구조적인 문제를 제기하며, 이 문제를 해결할 수 있는 효율적인 전이보시스템을 제안한다. 전이보시스템이 주각부에 발생하는 집중하중을 분산시키는 효과가 있는지 유한요소 프로그램인 ABAQUS를 통해 구조해석을 수행한다.

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The Stress -Strain Behavior of Sand in Torsion Shear Tests (비틀림전단시험에 의한 모래의 응력 -변형률 거동)

  • 남정만;홍원표
    • Geotechnical Engineering
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    • v.9 no.4
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    • pp.65-82
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    • 1993
  • A series of torsion shear tests were performed to study the drained stress -strain behavior of medium dense Santa Monica Beach sand under various stress paths. The torque was applied to both clockwise and counterclockwise directions at the end of hollow cylinder specimen. Two clip gages had been previously used to measure the changes in wall thickness and diameter of the specimen. In this study, however, the lateral strain was determined by measuring volume changes in specimen. Specimens were prepared by the air pluviation method and gaseous carbon deozide( CO2) was used to measure precisely volumetric strain in specimen. The drained stress -strain behavior of cohesionless Boils during rotation of principal stress directions was analysed based on the results of torsion shear tests. The coupling of mal stress were applied. It was also found from the test results that the atrial strain at failure decreased with increasing value.

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