• Title/Summary/Keyword: face element

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Prediction of Deformation Texture Based on a Three-Dimensional Crystal Plasticity Finite Element Method (3차원 결정소성 유한요소해석을 통한 변형 집합조직 예측)

  • Jung, K.H.;Kim, D.K.;Im, Y.T.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.21 no.4
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    • pp.252-257
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    • 2012
  • Crystallographic texture evolution during forming processes has a significant effect on the anisotropic flow behavior of crystalline material. In this study, a crystal plasticity finite element method (CPFEM), which incorporates the crystal plasticity constitutive law into a three-dimensional finite element method, was used to investigate texture evolution of a face-centered-cubic material - an aluminum alloy. A rate-dependent polycrystalline theory was fully implemented within an in-house program, CAMPform3D. Each integration point in the element was considered to be a polycrystalline aggregate consisting of a large number of grains, and the deformation of each grain in the aggregate was assumed to be the same as the macroscopic deformation of the aggregate. The texture evolution during three different deformation modes - uniaxial tension, uniaxial compression, and plane strain compression - was investigated in terms of pole figures and compared to experimental data available in the literature.

Study on the behaviour of pre-existing single piles to adjacent shield tunnelling by considering the changes in the tunnel face pressures and the locations of the pile tips

  • Jeon, Young-Jin;Jeon, Seung-Chan;Jeon, Sang-Joon;Lee, Cheol-Ju
    • Geomechanics and Engineering
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    • v.21 no.2
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    • pp.187-200
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    • 2020
  • In the current work, a series of three-dimensional finite element analyses have been conducted to investigate the behaviour of pre-existing single piles in response to adjacent tunnelling by considering the tunnel face pressures and the relative locations of the pile tips with respect to the tunnel. Via numerical modelling, the effect of the face pressures on the pile behaviour has been analysed. In addition, the analyses have concentrated on the ground settlements, the pile head settlements and the shear stress transfer mechanism at the pile-soil interface. The settlements of the pile directly above the tunnel crown (with a vertical distance between the pile tip and the tunnel crown of 0.25D, where D is the tunnel diameter) with a face pressure of 50% of the in situ horizontal soil stress at the tunnel springline decreased by approximately 38% compared to the corresponding pile settlements with the minimum face pressure, namely, 25% of the in situ horizontal soil stress at the tunnel springline. Furthermore, the smaller the face pressure is, the larger the tunnelling-induced ground movements, the axial pile forces and the interface shear stresses. The ground settlements and the pile settlements were heavily affected by the face pressures and the positions of the pile tip with respect to the tunnel. When the piles were inside the tunnel influence zone, tensile forces were induced on piles, while compressive pile forces were expected to develop for piles that are outside the influence zone and on the boundary. In addition, the computed results have been compared with relevant previous studies that were reported in the literature. The behaviour of the piles that is triggered by adjacent tunnelling has been extensively examined and analysed by considering the several key features in substantial detail.

A study on the behaviour of pre-existing single piles to adjacent shield TBM tunnelling from three-dimensional finite element analyses (3차원 유한요소해석을 통한 shield TBM 터널 근접시공에 의한 인접 단독말뚝의 거동에 대한 연구)

  • Jeon, Young-Jin;Jeon, Seung-Chan;Jeon, Sang-Joon;Lee, Cheol-Ju
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.22 no.1
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    • pp.23-46
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    • 2020
  • In the current work, a series of three-dimensional finite element analyses have been carried out to understand the behaviour of pre-existing single piles to adjacent tunnelling by considering the tunnel face pressures and the relative location of pile tips with respect to the tunnel. The numerical modelling has analysed the effect of the face pressures on the pile behaviour. The analyses concentrate on the ground settlements, the pile head settlements, the axial pile forces and the shear stress transfer mechanism at the pile-soil interface. The head settlements of the pile (the vertical distance between the pile and the tunnel: 0.25D, where D is the tunnel diameter) directly above the tunnel crown with the face pressure 50% of the in-situ horizontal soil stress at the tunnel springline decreased by about 38% compared to corresponding settlements with a face pressure 25% of the in-situ horizontal soil stress at the tunnel springline. Furthermore, it was found that the smaller the face pressure, the larger the tunnelling-induced ground movements and the axial pile forces were and the higher the degree of the shear strength mobilisation at the pile-soil interface. When the piles were outside the tunnel influence zone, compressive pile forces were developed due to tunnelling. It has been found that the ground settlements and the pile settlements are heavily affected by the face pressures and the position of the pile tip relative to the tunnel. In addition, the computed results have been compared with relevant studies previously reported in literature. The behaviour of the piles has been extensively examined and analysed by considering the key features in great detail.

Structure Analysis of Rubber Panel by Truck Weight (고무재를 사용한 판재의 차량하중에 의한 구조해석)

  • 윤성철
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.998-1002
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    • 2004
  • As the public use part of the railway and the road, the railway crossing is important to work properly by two transportation means. Also, It is important to provide the good face of friction on the railway crossing in aspect of protecting the railway crossing accident. Lately, Many kinds of the material are used for railway crossing panel. As they have a various fault, it was studied to analyze the structural action of the new material, rubber panel. This paper analyzed stress and displacement by truck passing weight using the Finite Element Modeling.

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A study on a collective behavior of interacting simple robots

  • Sugawara, Ken;Sano, Masaki;Watanabe, Toshinori
    • 제어로봇시스템학회:학술대회논문집
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    • 2002.10a
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    • pp.93.6-93
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    • 2002
  • Many livings form groups that we consider as collective systems. Their collective behaviors are good model for the development of useful distributed systems. In this paper, We discussed the group of motile elements that is described by simple model. The dynamics of each element is described by simple kinematics, but the group shows various types of motions. In addition, we found out the formation of the group changes by modifying rc which is an optimum distance between each element. This modification shows us to observe close-packed structure, face-centered lattice, sim pie lattice and double file.

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ANTIMUTAGENIC STUDY OF SELENIUM COMPOUNDS

  • Bronzetti, Giorgio;Leonardo Caltavuturo, Marco Cini;Croce, Clara Della
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2001.10a
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    • pp.10-10
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    • 2001
  • Selenium is an essential nutritional element for several animal species and human. It has been also seen, that low levels of selenium in the diet can cause many diseases. This metalloid was defined like a "double face" element because it possesses antioxidant, antimutagen, anticarcinogen but also mutagenic and carcinogenic effects. The most important metabolic role of selenium in the animal species is its presence in the Glutathione Peroxidase(GSH-Px). (omitted)

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Finite Element Analysis of Contact Pressure Behavior in Compression Ring-Oil Film (압축링-유막간의 접촉압력 거동에 관한 유한요소해석)

  • 김청균;김한구;한동철
    • Tribology and Lubricants
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    • v.11 no.4
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    • pp.53-57
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    • 1995
  • The contact pressure behavior is examined by means of a finite element analysis. The oil film between the piston ring and cylinder liner is analyzed on the basis that it behaves like a polymer material. The calculated results indicate that a shape of sloping edge with a straight line, which is designated as a Model III, shows a good performance on the contact pressure behavior for the increased speed. Obviously, the ring face profiles play an important role on the contact pressure between compression ring and oil film.

Finite element analysis on the hydroforming of bumper stay (하이드로포밍을 이용한 범퍼스테이 FEM 성형해석)

  • Kang B. H.;Kim B. J.;Ryu J. S.;Son S. M;Moon Y. H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.202-205
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    • 2004
  • A bumper comprises a bumper face, a bumper beam for distributing the load from the impacts applied to the bumper face and reinforcing the bumper, an absorber member interposed between the bumper face and the bumper beam, and a pair of bumper stays which secure the bumper beam to the vehicle body. A conventional bumper stay structure is assembled into several stamped parts, so several processes are needed and the structure is complicated. In this study the bumper stay is applied to the tubular hydroforming which is known to have several advantages such as the reduction of the number of the process and the part weight. The thickness distribution of the tube is mainly considered to evaluate the hydro-formability and the shape of the tube is determined.

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Automatic Estimation of 2D Facial Muscle Parameter Using Neural Network (신경회로망을 이용한 2D 얼굴근육 파라메터의 자동인식)

  • 김동수;남기환;한준희;배철수;권오흥;나상동
    • Proceedings of the IEEK Conference
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    • 1999.06a
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    • pp.1029-1032
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    • 1999
  • Muscle based face image synthesis is one of the most realistic approach to realize life-like agent in computer. Facial muscle model is composed of facial tissue elements and muscles. In this model, forces are calculated effecting facial tissue element by contraction of each muscle strength, so the combination of each muscle parameter decide a specific facial expression. Now each muscle parameter is decided on trial and error procedure comparing the sample photograph and generated image using our Muscle-Editor to generate a specific face image. In this paper, we propose the strategy of automatic estimation of facial muscle parameters from 2D marker movement using neural network. This also 3D motion estimation from 2D point or flow information in captered image under restriction of physics based face model.

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Crack Face Friction Effects on Mode II Stress Intensities for a Surface-Cracked Coating In Two-Dimensional Rolling $Contact^{\copyright}$ (구름접촉 하중시 코팅 표면에 발생한 균열면의 마찰을 고려한 모드II 전파거동에 관한 연구)

  • Moon Byung-Young;Kim Byeong Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.22 no.6 s.171
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    • pp.159-167
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    • 2005
  • This work focuses on the effects of crack free friction on Mode II stress intensity factors, $K_{II}$, for a vertical surface crack in a two-dimensional finite element model of TiN/steel subject to rolling contact. Results indicate that maximum $K_{II}$ values, which occur when the load is adjacent to the crack, may be significantly reduced in the presence of crack face friction. The reduction is more significant for thick coatings than for thin. Crack extension and increased layer thickness result in increased $K_{II}$ values. The effect of crack face friction on compressive $K_I$ values appears negligible. Comparative results are presented for $MoS_2/steel$ and diamond-like carbon(DLC)/Ti systems.