• 제목, 요약, 키워드: Shape design sensitivity

검색결과 299건 처리시간 0.051초

영구자석전동기의 코깅토오크저감을 위한 민감도에 의한 형상 최적화 (Shape Optimization for Reduction of Cogging Torque in Permanent Magnet Motor by Sensitivity Analysis)

  • 박일한;이범택;한현교;한송엽
    • 대한전기학회논문지
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    • v.39 no.12
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    • pp.1246-1252
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    • 1990
  • In order to reduce the cogging torque in a permanent magnet motor, a method to optimize the shape of permanent magnet and iron pole is presented. Sine the cogging torque comes from the irregular system energy variation according to the rotor position, system energy variation is taken as object function and the object function is minimized to optimize the shape. The positions of permanent magnet surface and iron pole surface are chosen as design parameters and sensitivity of object function with respect to the design parameter is calculated. The shape is changed according to sensitivity can be generated by methods that exploit the FEM formulation. A numerical example shows that the cogging torque is reduced to about 10% of the original value.

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경계요소법을 이용한 압축성형다이 가열선의 최적위치 설계 (Optimal Positioning of Heating Lines in a Compression Molding Die Using the Boundary Element Method)

  • 이부윤;조종래
    • 대한기계학회논문집
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    • v.17 no.6
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    • pp.1478-1485
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    • 1993
  • 본 연구에서는 압축 성형다이 가열선의 최적위치를 결정하는 문제를 다이의 형상 최적설계 문제로 정식화하고자 한다. 최적화 문제의 목적은 다이 내면의 온도를 지정된 온도로 균일하게 유지하는 것이다. 또한 Lee, Choi와 Kwak의 형상 설계 민감 도 해석을 위한 직접 미분 방법을 응용하여 가열선 위치변화에 관한 민감도 계산을 위한 경계 적분 방정식을 유도하고, 경계요소법으로 온도와 온도의 민감도를 해석하고 자 한다. 수치적 응용의 예로서, 넓은 평판의 성형을 위한 압축 성형다이의 가열선의 최적위치를 결정하는 문제를 다루고, 최적위치에서 가열선의 개수가 온도의 균일성에 미치는 영향을 검토한다.

설계 민감도법과 요소망 변형법을 이용한 3차원 비선형 전자소자의 형상최적화 (Shape Optimization of 3D Nonlinear Electromagnetic Device Using Design Sensitivity Analysis and Mesh Relocation Method)

  • 류재섭;;고창섭
    • 대한전기학회:학술대회논문집
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    • pp.124-127
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    • 2002
  • This paper presents a 3D shape optimization algorithm for electromagnetic devices using the design sensitivity analysis with finite element method. The structural deformation analysis based on the deformation theory of the elastic body under stress is used for mesh renewing. The design sensitivity and adjoint variable formulae are derived for the 3D nonlinear finite element method with edge element. The proposed algorithm is applied to the shape optimization of 3D electromagnet to get a uniform flux density at the air gap.

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고주파수 파워흐름 문제의 아이소-지오메트릭 형상 최적설계 (Isogeometric Shape Design Optimization of Power Flow Problems at High Frequencies)

  • 윤민호;하승현;조선호
    • 한국전산구조공학회논문집
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    • v.27 no.3
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    • pp.155-162
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    • 2014
  • 본 논문에서는 아이소-지오메트릭 해석법을 이용하여 고주파수를 가지는 파워흐름 문제에 대하여 연속체 기반 형상 최적 설계를 수행하였다. 아이소-지오메트릭 기법을 형상 최적설계에 적용하면, CAD 기하 모델링에서 쓰이던 NURBS 기저 함수가 직접 쓸 수 있기에 정확한 기하학 정보가 수치계산에서 고려되고, 이에 따라 형상 최적설계 관점에서 볼 때, 전통적인 유한요소법에 비해 향상되고 부드러운 설계 섭동량을 가지는 설계 매개화가 가능하게 된다. 즉, 정확한 기하 모델이 응답 해석과 설계민감도 해석에 쓰이게 되고, 이에 따라 설계영역 전체에서 법선 벡터와 곡률이 연속적으로 되게 된다. 결과적으로 정밀한 민감도 해석이 가능하게 된다. 몇 가지 수치예제를 통하여 개발된 아이소-지오메트릭 설계민감도가 유한차분 설계민감도와 비교하여 정확성을 확인할 수 있었으며, 형상 최적설계 문제를 통해서 본 방법론을 적용하여 검증하였다.

Optimum Shape Design of Magnetizing Yoke of 2 Pole PM Motor for Cogging Torque Reduction

  • Koh Chang-Seop;Ryu Jae-Seop;Hong Sun-Ki
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.5B no.2
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    • pp.168-172
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    • 2005
  • A novel cogging torque reduction algorithm is presented for 2-pole permanent magnet DC motor. While the shape of the permanent magnet is changed in the conventional method, the pole shape of the magnetizing yoke is optimized in the presented algorithm. In order to parameterize the shape of the yoke, and the distribution of the residual magnetization of the permanent magnet, the Bezier spline is used. The shape of the magnetizing yoke is optimized using the design sensitivity analysis incorporated with the finite element method and Bezier spline.

설계변수 매개화를 이용한 전기기기 최적설계 (Optimum Design of Electrical Apparatus Using Design Variable Parametrization)

  • 이형범;박일한;한송엽
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • v.50 no.11
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    • pp.546-555
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    • 2001
  • ln this paper, the optimum design of electrical apparatus using design variable parametrization is presented. For analysis and design, the finite element method and the design sensitivity method is used, respectively. By applying the parametrization of the design variables, the obtained designed shape is continuous and smooth. For the parametrization the Bezier spline is used. The designed shape with parametrization is characterized by the control points. By delivering control points to the commercial CAD packages or NC machines, the exact designed shape can be realized in the manufacturing the electrical apparatus. The designed results with and without parametrization are compared and the validity of the parametrization is verified.

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위상최적설계 기법을 이용한 이중편심 버터플라이 밸브의 디스크에 대한 형상설계 (SHAPE DESIGN FOR DISC OF A DOUBLE-ECCENTRIC BUTTERFLY VALVE USING THE TOPOLOGY OPTIMIZATION TECHNIQUE)

  • 양설민;백석흠;강상모
    • 한국전산유체공학회지
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    • v.17 no.1
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    • pp.61-69
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    • 2012
  • In this paper, the shape design process is briefly discussed emphasizing the use of topology optimization in the conceptual design stage. The basic idea is to view feasible domains for sensitivity region concepts. In this method, the main process consists of two steps: as the design moves further inside the feasible domain using Taguchi method, and thus becoming more successful topology optimization, the sensitivity region becomes larger. In designing a double-eccentric butterfly valve, related to hydrodynamic performance and disc structure, are discussed where the use of topology optimization has proven to dramatically improve an existing design and significantly decrease the development time of a shape design. CFD analysis results demonstrate the validity of this approach.

유한요소법에 의한 이중 금속봉 압출 공정의 금형 형상 최적설계 (Die Shape Optimal Design in Bimetal Extrusion by The Finite Element Method)

  • 변상민;황상무
    • 소성가공
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    • v.3 no.3
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    • pp.302-319
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    • 1994
  • A new approach to die shape optimal design in bimetal extrusion of rods is presented. In this approach, the design problem is formulated as a constrained optimization problem incorporated with the finite element model, and optimization of the die shape is conducted on the basis of the design sensitivities. The combinations of the core and sleeve materials.

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반해석적 방법을 이용한 고유치 문제의 형상 설계 민감도 향상에 관한 연구 (A study on the improvement of shape design sensitivity in eigenvalue problems using semi-analytical method)

  • 김현기;조맹효
    • 한국전산구조공학회:학술대회논문집
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    • pp.159-166
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    • 2001
  • Structural optimization often requires the evaluation of design sensitivities. The Semi Aanalytic method(SAM) for computing sensitivity is popular in shape optimization because this method has several advantages. But when relatively large rigid body motions are identified for individual elements, the SA method shows severe inaccuracy. In this paper, the improvement of design sensitivities corresponding to the rigid body mode is evaluated by exact differentiation of the rigid body modes. Moreover, the error of the SA method caused by numerical difference scheme is alleviated by using a series approximation for the sensitivity derivatives and considering the higher order terms. Finally, this paper shows that the refined SA method including the iterative method improves the results of sensitivity analysis in dynamic problems.

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압전 수정진동자의 설계민감도 해석과 위상 최적설계 (Design Sensitivity Analysis and Topology Optimization of Piezoelectric Crystal Resonators)

  • 하윤도;조선호;정상섭
    • 한국전산구조공학회:학술대회논문집
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    • pp.335-342
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    • 2005
  • Using higher order Mindlin plates and piezoelectric materials, eigenvalue problems are considered. Since piezoelectric crystal resonators produce a proper amount of electric signal for a thickness-shear frequency, the objective is to decouple the thickness-shear mode from the others. Design variables are the bulk material densities corresponding to the mass of masking plates for electrodes. The design sensitivity expressions for the thickness-shear frequency and mode shape vector are derived using direct differentiation method(DDM). Using the developed design sensitivity analysis (DSA) method, we formulate a topology optimization problem whose objective function is to maximize the thickness-shear component of strain energy density at the thickness-shear mode. Constraints are the allowable volume and area of masking plate. Numerical examples show that the optimal design yields an improved mode shape and thickness-shear energy.

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