• 반도체디스플레이기술학회지
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• 제10권3호
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• pp.61-65
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• 2011

The capabilities of finite elements codes allow now accurate simulations of blanking processes when appropriate materials modelling are used. Over the last decade, numerous numerical studies have focused on the influence of process parameters such as punch-die clearance, tools geometry and friction on blanking force and blank profile. In this study, three dimensional finite element analysis is carried out to design a lead frame blanking die using LS-Dyna3D package. After design of the blanking die, an experiment is also carried out to investigate the characteristics of blanking for nickel alloy Alloy42, a kind of IC lead frame material. In this paper, it has been researched the investigation to examine the influence of process parameters such as clearance and air cylinder pressure on the accuracy of sheared plane. Through the experiment results, it is shown that the quality of sheared plane is less affected by clearance and air cylinder pressure.

• 대한토목학회논문집
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• 제30권2D호
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• pp.135-141
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• 2010

국내 줄눈콘크리트 포장 다웰바의 경우 합리적 근거가 없이 경험에 의하거나 국외의 기준에 의해 설계시공되고 있다. 다웰바를 합리적으로 설계하기 위해서는 다웰바 거동에 대한 고찰이 요구되며 이에 3차원 유한요소해석을 이용하여 분석하였다. 다웰바의 거동을 평가하기 위해서 다웰바의 3차원 유한요소해석과 다웰바 거동에 대한 대표적인 모델인 Timoshenko 이론을 비교분석하였다. 본 연구에서는 다웰바의 사이즈 및 배치에 대한 합리적인 설계를 하기 위해서 3차원 유한요소해석을 사용하여 다웰바의 그룹작용(Dowel Group Action) 범위와 차량바퀴의 주행경로(Wheel Path)분포를 고려하여 슬래브 처짐을 감소시킬 수 있는 다웰바 최적배치를 제시하였다.

• 전기학회논문지
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• 제65권5호
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• pp.773-776
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• 2016

In the quasi-3D finite element(FE) anlysis, the overall characteristics of axial flux permanent magnet(AFPM) motor could be composed of each computation region. However, A drawback of quasi-3D FEM is not to consider the end effect on the stack end. To address this problem, an improved quasi-3D FE analysis which considers the end effect of the AFPM motor was proposed. From results the 3D FE analysis, the validity of the proposed method is verified.

• Computers and Concrete
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• 제7권6호
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• pp.497-510
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• 2010

For better estimation of elastic property of concrete composites, the effect of Interfacial Transition Zone (ITZ) has been found to be significant. Numerical concrete composites models have been introduced using Finite Element Method (FEM), where ITZ is modeled as a thin shell surrounding aggregate. Therefore, difficulties arise from the mesh generation. In this study, a numerical concrete composites model in 3D based on FEM and random unit cell method is proposed to calculate elastic modulus of concrete composites with ITZ. The validity of the model has been verified by comparing the calculated elastic modulus with those obtained from other analytical and numerical models.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제5B권3호
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• pp.229-232
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• 2005

Finite element method (FEM) is a very powerful tool for the calculation of magnetic field of electromagnetic devices. MATLAB/Simulink is also well known as a very useful tool for control systems. This paper proposes a very promising method, where the FEM is coupled with MATLAB. We apply this method to analyze a permanent magnet (PM) motor drive system, and compare with results using MATLAB only.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.125-127
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• 2001

Switched reluctance motor (SRM) has some advantages such as low cost, high torque density etc. However SRM has inevitably high torque ripple due to the double salient structure. To apply SRM to industrial field, we have to minimize torque ripple, which is the weak-Point of SRM. This paper presents optimal design process of SRM using numerical method such as 2D finite element method (FEM) and 3D equivalent magnetic circuit network method (EMCNM). The electrical and geometrical design parameters have been adopted as 2D design variables. The overhang structure of rotor has been also adopted as 3D design variable. From this work, we can obtain the optimal design, which minimize the torque ripple and maximize energy conversion loop.

• 한국자기학회지
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• 제6권2호
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• pp.106-111
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• 1996

전동기와 같이 가동부를 갖는 전기기기는 힘이나 토크를 발생시키기 위하여 고안되었고, 힘이나 토크는 이들 기기의 해석과 설계에 중요한 요소이다. 지금까지 유한요소법을 이용한 전자력 계산 방법으로는 여러가지 방법들이 제시되어 왔고, 그 중 널리 사용되는 방법으로는 맥스웰 응력법과 가상변위법이 있다. 맥스웰 응력법은 맥스웰 스트레스텐서를 이용하여 표면 전자력 밀도를 구하고 이의 표면 적분으로 전자력을 구하는 방법이고, 가상변위법은 물체에 변위가 일어났을 때 발생하는 에너지의 변화량을 이용하여 전자력을 구하는 방법이다. 전류원이 포함된 문제에서는 정확도를 높이기 위하여 벡터포텐셜을 주로 이용하여 자장해석을 하여 왔으므로 본 논문에서는 유한요소법으로 3차원 자장 문제를 해석한 결과인 자기벡터포텐셜을 맥스웰 응력법과 가상변위법에 적용하여 전기기계의 각 요소의 전자력을 구하는 방법을 제시한다. 제시한 방법의 검증을 위하여 해석 모델을 솔레노이드로 하여 제시한 방법으로 구한 전자력을 3차원으로 해석한 결과와 비교하여 그 유용성을 증명한다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1753-1755
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• 1996

This paper presents an analysis of the 3D microwave oven considering its forming. The results were compared with experimental data. Finite Element Method(FEM) using edge clement is employed for the analysis. For solving the large sparse system matrix equation was solved using the parallelized QMR method. Analysis of the 3d cavity has troublesome difficulties such as spurious solutions, too many memory and long computation time. We overcome this difficulties by using edge clement for spurious solutions and the parallelized QMR method by the aid of Paralle Virtual Machine(PVM) for the memory and computation time.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.517-519
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• 2007

We report our study on the implementation of Q tensor approach into three-dimensional finite element method (FEM) numerical solver. The comparative simulation results demonstrated the possibility of a different director configuration in between Q tensor method and vector method. The comparative study confirmed that Q Tensor implementation is more appropriate for OCB analysis than the vector method.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 A
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• pp.153-155
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• 1994

Electric machines such as motors which have moving parts are desgined for producing mechanical force or torque. The accurate calculation of electromagnetic force and torque is important in the design these machines, Electromagnetic force calculation method using the results of Finite Element Method(FEM) has been presented variously in 2-D problems. Typically the Maxwell's Stress Tensor method and the method of virtual work are used. In the problems including current source, magnetic vector potentials(MVP) have mostly been used as an unknown variables for field analysis by numerical method; e, g. FEM. This paper, thus, introduces both methods using MVP in 3-D case. To verify the usefulness of presented methods, a solenoid model is chosen and analyzed by 3-D and axisymmetrical FEM. In each case, the calculated force are tabulated for several mesh schemes.