• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.509-512
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• 2007

In this paper, we report our successful implementation of Q tensor model in threedimensional finite element method (FEM) simulator. The 3D-FEM Q tensor-model-based simulation revealed that the spaly-to-bend transition occurs only at 4 V while the vector-model based FEM solver provides an erroneous transition voltage of 8 V.

• Journal of Electrical Engineering and Technology
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• v.6 no.5
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• pp.618-625
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• 2011

This paper presents a double excited three degree-of-freedom (3DOF) motor. The proposed 3DOF motor is designed with a laminated structure, making it easy to manufacture. In addition, it has windings on the stator and rotor, and does not require an expensive permanent magnet. We explain the structure, principle of motion, and design of the proposed motor, and perform an analysis of the static characteristics using the two- and three-dimensional finite element methods (3D FEM). The feasibility of 3D FEM analysis is confirmed by comparing the 3D FEM analysis and experimental results for the rolling and pitching motion. We also confirm the occurrence of holding torque in every motion.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.670_671
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• 2009

This paper presents a optimum design process for static torque characteristics of the Claw-Poles PM Stepping Motor(CPSM). Since the shape of CPSM changes along with axial direction, CPSM should only be analyzed by 3D-FEM. But 3D-FEM needs too much computation time and computer resources. Therefore, it is essential to reduce the number of 3D-FEM analysis models. In this paper, two design factors which affect the static torque characteristics of CPSM were selected. Optimum design process was able to make progress by using Pattern Search Algorithm and 3D-FEM. Finally, optimized model was compared with a conventional model.

• Geomechanics and Engineering
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• v.11 no.1
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• pp.77-94
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• 2016

A forked tunnel, as a special complicated underground structure, is composed of big-arch tunnel, multi-arch tunnel, neighborhood tunnels and separate tunnels according to the different distances between two separate tunnels. Due to the complicated process of design and construction, surrounding jointed rock mass stability of the big-arch tunnel which belongs to the forked tunnel during excavation is a hot issue that needs special attentions. In this paper, an elasto-plastic damage constitutive model for jointed rock mass is proposed based on the coupling method considering elasto-plastic and damage theories, and the irreversible thermodynamics theory. Based on this elasto-plastic damage constitutive model, a three dimensional elasto-plastic damage finite element code (D-FEM) is implemented using Visual Fortran language, which can numerically simulate the whole excavation process of underground project and perform the structural stability of the surrounding rock mass. Comparing with a popular commercial computer code, three dimensional fast Lagrangian analysis of continua (FLAC3D), this D-FEM has advantages in terms of rapid computing process, element grouping function and providing more material models. After that, FLAC3D and D-FEM are simultaneously used to perform the structural stability analysis of the surrounding rock mass in the forked tunnel considering three different computing schemes. The final numerical results behave almost consistent using both FLAC3D and D-FEM. But from the point of numerically obtained damage softening areas, the numerical results obtained by D-FEM more closely approach the practical behaviors of in-situ surrounding rock mass.

• Proceedings of the KIEE Conference
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• 2006.07b
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• pp.839-840
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• 2006

This paper deals with skew and overhang effects of Permanent Magnet of PMLSM. The detent force and thrust characteristics considering skew and overhang effects of permanent magnet are analyzed by 3D FEM and the results are compared to experimental values

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.2107-2108
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• 2006

본 논문에서는 범용 공학 소프트웨어인 셈툴과 연계한 FEM 패키지의 3D Visualization 및 Operation에 대해 기술 한다. FEM 해석을 위한 Graphical Interface로서 각종 오브젝트의 생성, 로드와 더불어 해당 오브젝트를 3D Visualization하여 각종 Manipulation을 하는 기법에 대해 서술하도록 한다. 특히, 해석에 필요한 경계 조건이나 하중을 부여하기 위해 노드를 Picking 하는 기법과, 해석 후 객체의 내부 하중 상태 등에 대한 컨투어링을 위해 객체를 분할하는 Cut Section 등에 대해서도 다루도록 한다.

• Journal of Mechanical Science and Technology
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• v.20 no.10
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• pp.1722-1729
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• 2006

Predicting the mechanical properties of the 3-D scaffold using finite element method (FEM) simulation is important to the practical application of tissue engineering. However, the porous structure of the scaffold complicates computer simulations, and calculating scaffold models at the pore level is time-consuming. In some cases, the demands of the procedure are too high for a computer to run the standard code. To address this problem, the representative volume element (RVE) theory was introduced, but studies on RVE modeling applied to the 3-D scaffold model have not been focused. In this paper, we propose an improved FEM-based RVE modeling strategy to better predict the mechanical properties of the scaffold prior to fabrication. To improve the precision of RVE modeling, we evaluated various RVE models of newly designed 3-D scaffolds using FEM simulation. The scaffolds were then constructed using microstereolithography technology, and their mechanical properties were measured for comparison.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1306-1308
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• 2005

The characteristic of line start permanent magnet(LSPM) motor with overhang structure is analyzed using 3dimensional finite element method(3D FEM). We propose the appropriate overhang length by considering the magnetic flux distribution according to changing overhang length and manufacturing process. 3D FEM analysis is inevitable because the increase of the total flux cannot be appropriately considered in 2D FEM. In equal model specification total flux is recalculated at 3D FEM, because of considering lamination length. This paper compares the characteristic of Back-emf with and without overhang by permanent magnet that has identical volume.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.12
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• pp.2605-2614
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• 2002

This paper describes an analysis method based on the experimental parameter for the 0.9kW starter motor of vehicle with permanent magnet and pole core, and analyzed the influence by the effect of pole core of starting motor by using the 2D-FEM analysis technique to reflect the structural characteristic of 3D. A starter motor consists mainly of armature, yoke and permanent magnet with the pole core. Additionally, there is different the axial length of each part. Therefore, the effective of analysis method is needed to improve the characteristic of it. This paper approached the 2D-FEM analysis estimated by the 3D-EMCN(Three Dimensional Equivalent Magnetic Circuit Network) instead of the 3D-FEM analysis to minimize parameters. As a result, this paper is proposed the validity of 2D-FEM analysis and obtained reasonable results for improving a performance.

• International Journal of Aeronautical and Space Sciences
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• v.18 no.1
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• pp.63-69
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• 2017

In this paper, composite laminate pull-through resistance was analyzed using the FEM method and compared with test results. 2D and 3D simplified FEM models, a nonlinear analysis, and a progressive failure analysis utilizing three composite laminate failure theories Maximum Stress, Maximum Strain, and Tsai-Wu were used to predict the FEM results with the test results. The load and boundary conditions of the test were applied to the FEM to simulate the test. A composite laminate pull-through test (ASTM D7332 Proc. B) was designed with a special fixture to collect more precise data. The test results were compared with the FEM analysis results.