• Title/Summary/Keyword: 2-dimensional finite element method

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2.5 Dimensional Electromagnetic Finite Element Numerical modeling using linear conductivity variation (선형적 물성변화를 고려하는 유한요소법을 이용한 2.5차원 전자탐사 수치모델링)

  • Ko, Kwang-Beom;Suh, Baek-Soo
    • Journal of Industrial Technology
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    • v.18
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    • pp.131-138
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    • 1998
  • Numerical modeling for electromagnetic exploration methods are essential to understand behaviours of electromagnetic fields in complex subsurfaces. In this study, a finite element method was adopted as a numerical scheme for the 2.5-dimensional forward problem. And a finite element equation considering linear conductivity variation was proposed when 2.5-dimensional differential equation to couple eletric and magnetic field was implemented. Model parameters were investigated for near-field with large source effects and far-field with responses dominantly by homogeneous half-space. Numerical responses by this study were compared with analytic solutions in homogeneous half-space and compared with other three dimensional numerical results.

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Static Analysis of Two Dimensional Curbed Beam Structure by Finite Element-Transfer Stiffness Coefficent Method (유한요소-전달강성계수법에 의한 2차원 곡선 보 구조물의 정적해석)

  • Choi, Myung-Soo
    • Journal of Power System Engineering
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    • v.21 no.6
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    • pp.40-45
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    • 2017
  • The objective of this study is the finite element-transfer stiffness coefficient method, which is the combination of the modeling technique of finite element method and the transfer technique of transfer stiffness coefficient method, is applied in the static analyses of two dimensional curved beam structures. To confirm the effectiveness of the applied method, two computational models are selected and analyzed by using finite element method, finite element-transfer stiffness coefficient method and exact solution. The computational results of the static analyses for two computational models using finite element-transfer stiffness coefficient method are equal to those using finite element method. When the element partition number of curved beam structure is increased, the computational results of the static analyses using both methods approach the exact solution. We confirmed that the finite element-transfer stiffness coefficient method is superior to finite element method when the number of the curved beam elements is increased from the viewpoints of the computational speed and the utility of computer memory.

3-Dimensional Finite Element Analysis of Hemming for Automotive Outer Panels by Part Model Assembling Method (부분모델 합성법을 이용한 자동차 외판의 헤밍 공정에 대한 3차원 유한요소해석)

  • 김헌영;임희택;김형종;이우홍;박춘달
    • Transactions of Materials Processing
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    • v.13 no.2
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    • pp.115-121
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    • 2004
  • Hemming is the last farming process in stamping and determines external quality of automotive outer panels. Few numerical approaches using 3-dimensional finite element model have been applied to a hemming process due to small element size which is needed to express the bending behavior of the sheet around small die comer and comparatively big model size of automotive opening parts, such as side door, back door and trunk lid etc In this study, part model assembling method is suggested and applied to the 3-dimensional finite element simulation of flanging and hemming process far an automotive front hood.

Preconditioning Method of a Finite Element Combined Formulation for Fluid-Structure Interaction (유체-구조물 상호작용을 위한 유한요소 결합공식화의 예조건화에 대한 연구)

  • Choi, Hyoung-Gwon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.4
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    • pp.242-247
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    • 2009
  • AILU type preconditioners for a two-dimensional combined P2P1 finite element formulation of the interaction of rigid cylinder with incompressible fluid flow have been devised and tested by solving fluid-structure interaction (FSI) problems. The FSI code simulating the interaction of a rigid cylinder with an unsteady flow is based on P2P1 mixed finite element formulation coupled with combined formulation. Four different preconditioners were devised for the two-dimensional combined P2P1 finite element formulation extending the idea of Nam et al., which was proposed for the preconditioning of a P2P1 mixed finite element formulation of the incompressible Navier-Stokes equations. It was found that PC-III or PC-IV among them perform well with respect to computational memory and convergence rate for some bench-mark problems.

Analysis of PSC Box Girder Anchorage Zone using FEM and 2D SUB-3D STM Approach (유한요소법 및 유사 3 차원 스트릿-타이 모델 방법을 이용한 PSC 박스거더 정착부의 해석)

  • Yun, Young-Mook;Kim, Seung-Eock;Oh, Jin-Woo;Park, Jung-Woong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.4 no.2
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    • pp.113-129
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    • 2000
  • This study evaluates the behavior and strength of an anchorage zone of the prestressed concrete box girder bridge on the Kyungboo highway railroad using the 2D SUB-3D STM approach and a linear elastic finite element analysis. The 2D SUB-3D STM approach utilizes several two-dimensional sub strut-tie models that represent the compressive and tensile stress flows of each projected plane of the three-dimensional structural concrete in the selection of a three dimensional strut-tie model, evaluation of the effective strengths of the concrete struts, and verification of the geometric compatibility condition and bearing capacity of the critical nodal zones in the selected three-dimensional strut-tie model. The finite element analysis uses an 8-node brick element and the longitudinal prestressing force is considered as the equivalent nodal force. Analysis results show that the 2D SUB-3D STM approach and linear elastic finite element method can be effectively applied to the analysis and design of three-dimensional structural concrete including a prestressed concrete box girder anchorage zone.

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The Analysis of H-Shape Rolling by the Finite Element Method (유한요소법에 의한 H형강 압연공정의 해석)

  • 신현우;김낙수;박종진
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.5
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    • pp.1095-1105
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    • 1993
  • Shape rolling processes to produce H-section beams are numerically simulated by the simplified three-dimensional finite element method. The 2-dimensional finite element method, used for the generalized plane strain condition, is combined with the slab method. Computer simulation results of the 19-passes in H-section beam rolling in practice include the grid distortions, the cross-sectional area changes, the roll separating forces, and the roll torques. Also, the amount of side spread can be found during the multi-pass rolling simulations. The finite element mesh system is remeshed with I-DEAS whenever the billet distorts severely. This study would contribute to CAD/CAM of shape rolling process through the optimal roll pass schedule.

A new numerical modelling for evaluating the stress intensity factors in 3-D fracture analysis

  • Cao, Zongjie;Liu, Yongyu
    • Structural Engineering and Mechanics
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    • v.43 no.3
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    • pp.321-336
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    • 2012
  • As an improvement on the isoparametric element method, the derivation presented in this paper is close to that done by Wang (1990) for the 2-D finite element. We extend this idea to solve 3-D crack problems in this paper. A new displacement modelling is constructed with local solutions of three-dimensional cracks and a quasi-compatible isoparametric element for three-dimensional fracture mechanics analysis is presented. The stress intensity factors can be solved directly by means of the present method without any post-processing. A new method for calculating the stress intensity factors of three-dimensional cracks with complex geometries and loads is obtained. Numerical examples are given to demonstrate the validity of the present method. The accuracy of the results obtained by the proposed element is demonstrated by solving several crack problems. The results illustrate that this method not only saves much calculating time but also increases the accuracy of solutions. Because this quasi-compatible finite element of 3-D cracks contains any singularities and easily meets the requirement of compatibility, it can be easily implemented and incorporated into existing finite element codes.

Predicting Method of Rosidual Stress Using Artificial Neural Network In $CO_2$ Are Weldling (인공신경망을 이용한 탄산가스 아크용접의 잔류응력 예측)

  • 조용준;이세현;엄기원
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.482-487
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    • 1993
  • A prediction method for determining the welding residual stress by artificial neural network is proposed. A three-dimensional transient thermomechanical analysis has been performed for the CO $_{2}$ Arc Welding using the finite element method. The validity of the above results is demonstrated by experimental elastic stress relief method which is called Holl Drilling Method. The first part of numarical analysis performs a three-dimensional transient heat transfer anslysis, and the second part then uses results of the first part and performs a three-dimensional transient thermo-clasto-plastic analysis to compute transient and residual stresses in the weld. Data from the finite element method were used to train a backpropagation neural network to predict residual stress. Architecturally, the finite element method were used to train a backpropagation voltage and the current, a hidden layer to accommodate failure mechanism mapping, and an output layer for residual stress. The trained network was then applied to the prediction of residual stress in the four specimens. The results of predicted residual stress have been very encouraging.

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Stochastic Finite Element Aalysis of Space Truss by Neumann Expansion Method (뉴우먼 확장법에 의한 3차원 트러스의 확률유한요소해석)

  • 정영수;김기정
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1993.04a
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    • pp.117-124
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    • 1993
  • The Neumann Expansion method has been used for evaluating the response variability of three dimensional truss structure resulting from the spatial variability of material properties with the aid of the finite element method, and in conjunction with the direct Monte Carlo simulation methods. The spatial variabilites are modeled as three-dimensional stochastic field. Yamazaki 〔1〕 has extended the Neumann Expansion method to the plane-strain problem to obtain the response variability of 2 dimensional stochastic systems. This paper presents the extension of the Neumann Expansion method to 3 dimensional stochastic systems. The results by the NEM are compared with those by the deterministic finite element analysis and by the direct Monte Carlo simulation method

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