• Journal of international Conference on Electrical Machines and Systems
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• 제3권3호
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• pp.325-330
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• 2014

Eddy current induction is used in a wide range of electronic devices, for example in detection sensors. Due to the advances in computer hardware and software, the need for 3D computation and system comprehension is a requirement to develop and optimize such devices nowadays. Pure theoretical models are mostly limited to special cases. On the other hand, the classical use of commercial Finite Element (FE) electromagnetic 3D models is not computationally efficient and lacks modeling flexibility or robustness. The proposed approach focuses on: (1) implementing theoretical formulations in 3D (FE) model of a detection device as well as (2) an automatic Volumetric Estimation Method (VEM) developed to selectively model the target finite elements. Due to these two approaches, this model is suitable for parametric studies and optimization of the number, location, shape, and size of PCB receivers in order to get the desired target discrimination information preserving high accuracy with tenfold reduction in computation time compared to commercial FE software.

• 한국지반공학회논문집
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• 제23권10호
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• pp.133-150
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• 2007

본 논문에서는 연약지반의 기초구조물로서 지오그리드 보강 쇄석기둥 공법(Geogrid-Encased Stone Column, GESC)이 시공되는 조건을 대상으로 3차원 유한요소해석 모델링측면에서 중요하게 다뤄져야 하는 내용을 고찰하였다. 이를 위해 GESC 보강개념 및 시공방법을 고찰하였으며, 유한요소모델링을 수행하여 점토지반의 압밀과 쇄석기둥 공법에 대한 모델 검증 및 응력-간극수압 연계해석을 수행하였다. 연약지반 성토제방에 적용된 GESC공법의 유한요소해석 결과를 통해 제방의 효율적인 거동평가를 위해서는 3차원 유한요소 해석 및 지오리드의 인장특성을 모사할 수 있는 멤브레인 요소의 고려 여부가 큰 영향을 미치는 것으로 나타났으며, GESC공법이 적용된 제방의 연계해석 모델링시 중요하게 고려되어야할 사항을 제시하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.605-607
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• 2000

Although Equvalent Magnetic Circuit (EMC) method. Using lumped parameter and numerical analysis method are widely used for electric machine analysis. these are neither always accurate enough nor sometimes available to easily use. Moreover three dimensional finite element method (3D-FEM) is inherently unsuitable for electric machine performance evaluation due to its poor computational efficiency, such as too long calculation time and difficulty in modeling for analysis. In this paper, Nonlinear Equivalent Magnetic Circuit (NEMC) method in combination with 2D-FEM is proposed to analyze the electric machine requiring 3D-FEM, and this method applys to torque evaluation for rotary actuator of Electro Magnetic Electronic Controller Power Steering (EM-ECPS).

• 전기학회논문지
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• 제60권5호
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• pp.942-948
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• 2011

This paper deals with characteristic analysis of axial flux permanent magnet (AFPM) machines with axially magnetized PM rotor using quasi-3-D analysis modeling. On the basis of magnetic vector potential and a two-dimensional (2-D) polar-coordinate system, the magnetic field solutions due to various PM rotors are obtained. In particular, 3-D problem, that is, the reduction of magnetic fields near outer and inner radius of the PM is solved by introducing a special function for radial position. And then, the analytical solutions for back-emf and torque are also derived from magnetic field solutions. The predictions are shown in good agreement with those obtained from 3-D finite element analyses (FEA). Finally, it can be judged that analytical solutions for electromagnetic quantities presented in this paper are very useful for the AFPM machines in terms of following items : initial design, sensitivity analysis with design parameters, and estimation of control parameters.

• 한국자동차공학회논문집
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• 제12권4호
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• pp.173-180
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• 2004

The tread pattern of a tire has an important effect on tire performances such as handling, wear, noise, hydroplaning and so on. However, a finite element analysis of a patterned tire with detailed tread blocks has been limited owing to the complexity of making meshes for tread blocks and the huge computation time. The computation time has been shortened due to the advance in the computer technology. The modeling of tread blocks usually requires creating a solid model using a CAD software. Therefore it is a very complicated and time-consuming job to generate meshes of a patterned tire using a CAD model. A new efficient and convenient method for generating meshes of a patterned tire has been developed. In this method, 3-D meshes of tread pattern are created by mapping 2-D meshes of tread geometry onto 3-D tread surfaces and extruding them through tread depth. Then, the tread pattern meshes are assembled with the tire body meshes by the tie contact constraint. Residual aligning torque and frictional energy are calculated by using a patterned tire model and compared to the experimental results. It is shown that the calculated results of a patterned tire model are in a good agreement with the experimental ones.

• 대한의용생체공학회:의공학회지
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• 제20권5호
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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.

• 한국철도학회논문집
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• 제14권1호
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• pp.11-18
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• 2011

본 논문은 열차의 타고오름 해석을 위한 새로운 2차원 다물체 동역학 모델링 방법을 제안하였다. 본 동역학 모델은 에너지 흡수구조/부품뿐만 아니라 차체의 변형도 고려하여 비선형 스프링, 댐퍼, 질량으로 구성되며 철도차량의 충돌에너지흡수량, 승객구간의 가속도, 연결 장치의 충격력, 차량간 타고오름 변위 등을 잘 예측할 수 있다. 제안된 방법으로 한국형고속열차를 차체 각 부분의 압괴 특성을 구하고 2차원 다물체 충돌동역학 모델을 구성하였다. 열차 대 열차 충돌 시나리오조건으로 2차원 동역학 모델을 시뮬레이션하고 3차원 가상시험 모델로 평가하였다. 그 결과 2차원 동역학 모델은 타고오름 거동을 잘 예측하였으며 차체변형을 고려한 모델링 기법이 타고오름 평가에 중요함을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제32권2호
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• pp.250-255
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• 2008

Springs are widely utilized in machine element. To find out stiffness of frustum-shaped coil spring, the space beam theory using the finite element method is adopted in this paper. In three dimensional space, a space frame element is a straight bar of uniform cross section which is capable of resisting axial forces, bending moments about two principal axes in the plane of its cross section and twisting moment about its centroidal axis. The corresponding displacement degrees of freedom are twelve. To find out load vector of coil spring subjected to distributed compression. principle of virtual work is adapted. And this theory was programming using MATLAB software. To compare FEM using MATLAB software was applied MSC. Nastran software. The geometry model for MSC. Patran was produced by 3-D design modeling software. Finite element model was produced by MSC. Patran. Finite element was applied tetra (CTETRA) having 10 node. The analysis results of the MATLAB and MSC. Nastran are fairly well agreed with those of various experiments. Using MATLAB program proposed in this paper and MSC. Nastran, spring constants and stresses can be predicted by input of few factors.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.398-405
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• 1997

The finite element program is presented for the analysis of the moment distribution in continuous slabs of simply supported girders. The program includes the material nonlinearity of the continuous and steel reinforcements of the RC slabs, but assumes that the PC beam and cross beam behave linearly. In modeling the PC slabs and girders, the four node degenerated shell element formulated based on the assumed strain interpolation and the 3D beam element are used, respectively. Using the program, the influence of the existence of the cross bean, the filling of open joints on the continuous at supports, and perfect continuation of precast girder elements are examined.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.29-34
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• 2008

A modeling technique for the 2-way coupling of heat transfer and conduction currents has been performed to inspire a combined analytical simulation. The 3-D finite element method is used to solve steady conduction currents and heat generation in an aluminum film deposited on a silicon substrate. The model investigates the temperature in the device after the current is applied. The conservation equation of energy, the Maxwell equations for conduction currents, the unsteady state heat transfer equation and the Fourier's law for heat transfer are implemented as a bidirectionally coupled problem. It is found that the strongly coupled temperature and time dependent heat equations give a reasonable results and an explicit solving technique.