• Title/Summary/Keyword: Geometrical Modeling

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Development of an Internet based Virtual Reality Environment and Web Database for the Integrity Evaluation of the Nuclear Power Plant (원자력발전소 건전성평가를 위한 인터넷기반 가상현실환경과 웹데이터베이스의 개발)

  • 김종춘;정민중;최재붕;김영진;표창률
    • Korean Journal of Computational Design and Engineering
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    • v.6 no.2
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    • pp.140-146
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    • 2001
  • A nuclear Power Plant is composed of a number of mechanical components. Maintaining the integrity of these components is one of the most critical issues in nuclear industry. In order to evaluate the integrity of these mechanical components, a lot of data are required including inspection data, geometrical data, material properties, etc. Therefore, an effective database system is essential to manage the integrity of nuclear power plant. For this purpose, an internet based virtual reality environment and web database system was proposed. The developed virtual reality environment provides realistic geometrical configurations of mechanical components using VRML (Virtual Reality Modeling Language). The virtual reality environment was linked with the web database, which can manage the required data for the integrity evaluation. The proposed system is able to share the information regarding the integrity evaluation through internet, and thus, will be suitable for an integrated system for the maintenance of mechanical components.

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Modeling Method of the TRNSYS Considering of a Building Geometry (건물의 기하학적 형태를 고려한 TRNSYS 모델링 방법)

  • Lee, Jae-Hyuk;Choi, Won-Ki;Suh, Seung-Jik
    • Proceedings of the SAREK Conference
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    • 2009.06a
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    • pp.21-26
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    • 2009
  • TRNSYS 16 had just a wall area and azimuth as an input value about a building shape. So, a geometrical shape of a building was not considered in simulation using TRNSYS 16. In this study, we suggested the more appropriate modeling method for simulation considering of building geometry in TRNSYS 16. To suggest this method, we simulated energy needs affected by shading effect that caused by a geometrical shape of a building, and compared the result to the simulation result of non-shading environment.

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Comparision of 3-D Geometrical Modelling of the Lumbar Spine Using Parameterized and Cross-sectional CT Image Reconstruction Method (요추에 있어서 파라미터 기법과 단면CT영상을 이용한 3차원 형상 모델링의 비교)

  • Kim, S.M.;Kim, S.J.;Tack, K.R.;Kim, N.H.
    • Proceedings of the KOSOMBE Conference
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    • v.1998 no.11
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    • pp.159-160
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    • 1998
  • In this study, a three-dimensional geometrical parameterized finite element modeling of the lumbar spine is compared with the 3-D reconstruction model from 2-D CT image. feasibility and accuracy of the parameterized modeling method is evaluated compared with conventional 3-D reconstruction method from 2-D CT image.

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A hybrid approach for character modeling using geometric primitives and shape-from-shading algorithm

  • Kazmin, Ismail Khalid;You, Lihua;Zhang, Jian Jun
    • Journal of Computational Design and Engineering
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    • v.3 no.2
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    • pp.121-131
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    • 2016
  • Organic modeling of 3D characters is a challenging task when it comes to correctly modeling the anatomy of the human body. Most sketch based modeling tools available today for modeling organic models (humans, animals, creatures etc) are focused towards modeling base mesh models only and provide little or no support to add details to the base mesh. We propose a hybrid approach which combines geometrical primitives such as generalized cylinders and cube with Shape-from-Shading (SFS) algorithms to create plausible human character models from sketches. The results show that an artist can quickly create detailed character models from sketches by using this hybrid approach.

Geometrical dimensions effects on the seismic response of concrete gravity dams

  • Sevim, Baris
    • Advances in concrete construction
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    • v.6 no.3
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    • pp.269-283
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    • 2018
  • This study presents the effects of geometrical dimensions of concrete gravity dams on the seismic response considering different base width/dam height (L/H) ratios. In the study, a concrete gravity dam with the height of 200 m is selected and finite element models of the dam are constituted including five different L/H ratios such as 0.25, 0.5, 0.75, 1.00, 1.25. All dams are modeled in ANSYS software considering dam-reservoir-foundation interaction. 1989 Loma Prieta earthquake records are applied to models in upstream-downstream direction and linear time history analyses are performed. Dynamic equilibrium equations of motions obtained from the finite element models of the coupled systems are solved by using Newmark time integration algorithm. The seismic response of the models is evaluated from analyses presenting natural frequencies, mode shapes, displacements and principal stresses. The results show that the L/H ratios considerably affect the seismic response of gravity dams. Also, the model where L/H ratio is 1.00 has more desirable results and most appropriate representation of the seismic response of gravity dams.

Finite strip analysis of a box girder simulating the hull of a ship

  • Akhras, G.;Tremblay, J.P.;Graham, T.;Cheung, M.S.;Li, W.C.
    • Structural Engineering and Mechanics
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    • v.15 no.2
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    • pp.225-238
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    • 2003
  • In the present study, the finite strip analysis of a box girder to simulate a ship's hull model is carried out to investigate its inelastic post-buckling behavior and to predict its ultimate flexural strength. Residual stresses and initial geometrical imperfections are both considered in the combined material and geometrical nonlinear analysis. The von-Mises yield criterion and the Prandtl-Reuss flow theory of plasticity are applied in modeling the elasto-plastic behavior of material. The Newton-Raphson iterative process is also employed in the analysis to achieve convergence. The numerical results agree well with the experimental data. The effects of some material and geometrical parameters on the ultimate strength of the structure are also investigated.

Surface Modeling and 5-axis NC machining of Automobile Tire Model (자동차 타이어 모델의 곡면 모델링 및 5축 NC 가공)

  • Lee, Cheol-Soo
    • IE interfaces
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    • v.9 no.2
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    • pp.129-141
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    • 1996
  • Recently, the tire mold of a passenger car is made almost via aluminum casting, and it is necessary to prepare a master model of the tire for the casting. Because of the geometrical feature of tire, as well known, the master model must be machined by a 5-axis NC machine. The paper proposes a procedure to model and machine the master model. The approach includes (a) transformation of 2D drawing of tire into 3D geometry, (b) modeling surfaces of tire, and (c) inverse kinematics of a 5-axis NC machine. An implementation of the proposed procedure is also presented.

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Forced vibration of nanorods using nonlocal elasticity

  • Aydogdu, Metin;Arda, Mustafa
    • Advances in nano research
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    • v.4 no.4
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    • pp.265-279
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    • 2016
  • Present study interests with the longitudinal forced vibration of nanorods. The nonlocal elasticity theory of Eringen is used in modeling of nanorods. Uniform, linear and sinusoidal axial loads are considered. Dynamic displacements are obtained for nanorods with different geometrical properties, boundary conditions and nonlocal parameters. The nonlocal effect increases dynamic displacement and frequency when compared with local elasticity theory. Present results can be useful for modeling of the axial nanomotors and nanoelectromechanical systems.

Surface Modeling of Forebody's Hull Form Using Form Parameters and Fair-Skinning (형상 파라메터와 평활화 스키닝을 이용한 선수 선형 곡면 모델링)

  • Kim, Hyun-Cheol;HwangBo, Seung-Myun
    • Journal of the Society of Naval Architects of Korea
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    • v.45 no.6
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    • pp.601-610
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    • 2008
  • This paper deals with a new geometrical surface modeling method of forebody's hull form which is fully defined by form parameters. The complex hull form in the forebody can be modeled by the combination of three parts: bare hull, bulbous bow and blending part which connects a bare hull and a bulbous bow. All these subdomain parts are characterized by each own form parameters and constructed with simple surface model. For this, we need only 2-dimensional hull form data and then the form parameters are calculated automatically from these data. Finally, the smooth hull form surfaces are generated by parametric design and fair-skinning. In the practical point of view, we show that this new method can be useful and efficient modeling tool by applying to the hull form surface modeling of Panamax container's forebody.