• Title/Summary/Keyword: 3차원 FEM모델링

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Efficient 3D Modeling of CSEM Data (인공송신원 전자탐사 자료의 효율적인 3차원 모델링)

  • Jeong, Yong-Hyeon;Son, Jeong-Sul;Lee, Tae-Jong
    • 한국지구물리탐사학회:학술대회논문집
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    • 2009.10a
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    • pp.75-80
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    • 2009
  • Despite its flexibility to complex geometry, three-dimensional (3D) electromagnetic(EM) modeling schemes using finite element method (FEM) have been faced to practical limitation due to the resulting large system of equations to be solved. An efficient 3D FEM modeling scheme has been developed, which can adopt either direct or iterative solver depending on the problems. The direct solver PARDISO can reduce the computing time remarkably by incorporating parallel computing on multi-core processor systems, which is appropriate for single frequency multi-source configurations. When limited memory, the iterative solver BiCGSTAB(1) can provide fast and stable convergence. Efficient 3D simulations can be performed by choosing an optimum solver depending on the computing environment and the problems to be solved. This modeling includes various types of controlled-sources and can be exploited as an efficient engine for 3D inversion.

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A Study on Automated 3-D Reconstruction Based on 2-D CT Image of Lumber Spine (요추의 2차원 CT 영상을 이용한 3차원 형상모델링의 자동화 연구)

  • 김성민;김성재;서성영;탁계례
    • Journal of Biomedical Engineering Research
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    • v.20 no.5
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    • pp.581-586
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    • 1999
  • 척추의 생체역학적 해석을 위한 유한요소기법을 이용한 컴퓨터 시뮬레이션은 척추의 손상에 대한 발생원인과 기전을 이해하고 치료의 효과를 예측하는 유용한 수단으로 기대되고 있다. 본 논문에서는 요추의 2차원 CT 영상을 이용하여 유한요소해석을 위한 척추의 3차원 모델링에 소비되는 많은 시간을 줄일 수 있도록 3차원 형상모델을 CT 형상 데이터와 형상변수를 이용, 각각 구현하는 과정을 자동화하여 이를 비교하였다.

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Two-dimensional Resistivity Modeling Using Boundary Elements Method (경계 요소법을 이용한 2차원 비저항 모델링)

  • 김형수
    • The Journal of Engineering Geology
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    • v.6 no.3
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    • pp.119-130
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    • 1996
  • The theory and numerical technique using boundary elements method (BEM) are given to solve 2-dimensional resistivity problems. Potential distributions from homogeneous resistivity model and layered model are calculated by using BEM for a point source of current injection. The potential distributions of BEM are compared with those of finite difference method (FDM) and finite elements method (FEM). Among the three numerical methods to solve 2-dimensional resistivity problem, it is proved that BEM is more efficient tool than FDM and FEM in consideration of computing storage and time as weU as the accuracy of solutions.

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Three-Dimensional High-Frequency Electromagnetic Modeling Using Vector Finite Elements (벡터 유한 요소를 이용한 고주파 3차원 전자탐사 모델링)

  • Son Jeong-Sul;Song Yoonho;Chung Seung-Hwan;Suh Jung Hee
    • Geophysics and Geophysical Exploration
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    • v.5 no.4
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    • pp.280-290
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    • 2002
  • Three-dimensional (3-D) electromagnetic (EM) modeling algorithm has been developed using finite element method (FEM) to acquire more efficient interpretation techniques of EM data. When FEM based on nodal elements is applied to EM problem, spurious solutions, so called 'vector parasite', are occurred due to the discontinuity of normal electric fields and may lead the completely erroneous results. Among the methods curing the spurious problem, this study adopts vector element of which basis function has the amplitude and direction. To reduce computational cost and required core memory, complex bi-conjugate gradient (CBCG) method is applied to solving complex symmetric matrix of FEM and point Jacobi method is used to accelerate convergence rate. To verify the developed 3-D EM modeling algorithm, its electric and magnetic field for a layered-earth model are compared with those of layered-earth solution. As we expected, the vector based FEM developed in this study does not cause ny vector parasite problem, while conventional nodal based FEM causes lots of errors due to the discontinuity of field variables. For testing the applicability to high frequencies 100 MHz is used as an operating frequency for the layer structure. Modeled fields calculated from developed code are also well matched with the layered-earth ones for a model with dielectric anomaly as well as conductive anomaly. In a vertical electric dipole source case, however, the discontinuity of field variables causes the conventional nodal based FEM to include a lot of errors due to the vector parasite. Even for the case, the vector based FEM gave almost the same results as the layered-earth solution. The magnetic fields induced by a dielectric anomaly at high frequencies show unique behaviors different from those by a conductive anomaly. Since our 3-D EM modeling code can reflect the effect from a dielectric anomaly as well as a conductive anomaly, it may be a groundwork not only to apply high frequency EM method to the field survey but also to analyze the fold data obtained by high frequency EM method.

FEM Analysis of Cleaning Machines by Design Change (설계 변경된 세척기의 유한요소해석)

  • Lee, Jong-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.10
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    • pp.5950-5954
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    • 2014
  • FEM analysis of cleaning machine was performed. A cleaning machine was designed and measured to develop a cleaning machine with highly improved performance and a real configuration. 3D modeling was conducted using the 3-D design program CATIA V5. In addition, FEM analysis was conducted on the modeled cleaning machine using the ANSYS finite element analysis program and the pressure changes in internal fluid flow were visualized. This result was applied to the new product development of cleaning machines.

Finite Element Method Analysis of Safety Valve (안전밸브의 유한요소해석)

  • Lee, Jong-Sun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.9
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    • pp.3864-3868
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    • 2012
  • In this paper, a safety valve was modeled by using 3-dimensional designing program, Solidsworks after it was dismantled and measured. And 3-dimensional finite element analysis code, ANSYS was used to FEM analysis. Stress, strain and deformation were obtained when some amount of pressure was applied to the safety valve through FEM analysis.

Characteristic Analysis of Eddy Current Testing According to the finite Element formulations (와전류탐상의 3차원 유한요소 정식화에 따른 특성 분석)

  • Lee, Hyang-Beom
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.5
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    • pp.384-390
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    • 2005
  • In the numerical analysis of En (eddy current testing) using 3-dimensional FEM (finite element method), MVP (magnetic vector potential) and electric scalar potential are used as variables in conductor region. Three dimensional modeling makes number of unknowns increase, and the degree of freedom of variables also makes number of unknowns increase. Because of this reason, modified UP is used to reduce the number of unknowns. Gauge condition is enforced artificially on existing FEM formulations to insure the uniqueness of MVP. So in this paper the effects of these FEM formulation procedures on ECT are investigated and the appropriate FEM formulation is suggested for accurate ECT simulation.

The Assesment of Tunnelling Induced Damage for the Opera House (Emphasis on 3D FEM Analysis) (터널 시공에 따른 오페라극장의 영향평가 (수치해석을 중심으로))

  • Hwang, Eui-Seok;Lee, Bong-Youl;Kim, Hak-Moon
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.4 no.1
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    • pp.3-12
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    • 2002
  • This research work is to investigate influences of the Opera House in Arts Center caused by the twin tunnel construction. The Opera House of 3D structural feature with various type of foundations and adjacent twin tunnels are modeled in 3-Dimensional mesh for FEM analysis. Confirmation of safety is essential for this particular type of structure, and attention level and warning level of control criteria are examined for the protection of the Opera House by means of the analytical results.

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A Comparative Study of 3D MT Modeling Methods (3차원 MT 모델링 기법의 비교 분석)

  • Han, Nu-Ree;Nam, Myung-Jin;Kim, Hee-Joon;Song, Yoon-Ho;Suh, Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.10 no.2
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    • pp.154-160
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    • 2007
  • This paper compares the characteristics of three different algorithms for three-dimensional (3D) magnetotelluric (MT) modeling. These methods are developed by Mackie et al. (1994), Sasaki (1999) and Nam et al. (2007). The first and second methods are based on the finite difference method (FDM), while the last one the finite-element method (FEM). MT responses, apparent resistivities and phases, for a COMMEMI 3D-2 model show a good agreement with integral equation solutions and only minor discrepancies are found over the anomalous bodies in the 3D model. The computation time of the two methods based on FDM is short and the static divergence correction contributes to speed up. The FEM modeling scheme is accurate but slow.