• 제목/요약/키워드: Shape Design Sensitivity Analysis

검색결과 230건 처리시간 0.022초

3D Optimal Design of Transformer Tank Shields using Design Sensitivity Analysis

  • Yingying Yao;Ryu, Jae-Seop;Koh, Chang-Seop;Dexin Xie
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
    • /
    • 제3B권1호
    • /
    • pp.23-31
    • /
    • 2003
  • A novel 3D shape optimization algorithm is presented for electromagnetic devices carry-ing eddy current. The algorithm integrates the 3D finite element performance analysis and the steepest descent method with design sensitivity and mesh relocation method. For the design sensitivity formula, the adjoint variable vector is defined in complex form based on the 3D finite element method for eddy current problems. A new 3D mesh relocation method is also proposed using the deformation theory of the elastic body under stress to renew the mesh as the shape changes. The design sensitivity f3r the sur-face nodal points is also systematically converted into that for the design variables for the parameterized optimization application. The proposed algorithm is applied to the optimum design of the tank shield model of the transformer and the effectiveness is proved.

전기기기 최적형상 설계를 위한 민감도 해석에 관한 연구 (Sensitivity Analysis for Optimum Shape Design of Electric Apparatus)

  • Hahn, Song-Yop;Jung, Hyun-Kyo
    • 대한전기학회논문지
    • /
    • 제40권9호
    • /
    • pp.859-865
    • /
    • 1991
  • This paper presents a new shaoe optimal design method using Desing Sensitivity Analysis. Design Sensitivity, defined as the variation of the object function with respect to the design variables, is based on the total differentiation of the matrix equation obtained from discretization of governing equations with respect to design variables. Analysis of the various characteristics adn calculation of Design Sensitivity of optimization model are achieved by using finite or boundary element methods. The proposee algorithm is applied to the optimal shape design of high voltage electrode under specified conditions. It is shown, from the numerical results, that the algorithm is very useful for the optimal shape design of electric apparatus.

설계민감도해석과 FEM에 의한 전자소자의 형상최적화 (Design Sensitivity Analysis for Shape Optimization of Electromagnetic Device with Finite Element Method)

  • 류재섭;고창섭
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2002년도 하계학술대회 논문집 B
    • /
    • pp.835-837
    • /
    • 2002
  • This paper presents a shape optimization algorithm of electromagnetic devices using the design sensitivity analysis with FEM. The design sensitivity and adjoint variable formulas are derived for the 3D FEM with edge element. This algorithm is applied to 3D electro-magnet pole shape optimization problem to make a uniform flux density at the target region.

  • PDF

경계법을 이용한 형상최적화 문제의 설계민감도 해석 및 응용 (A Boundary Method for Shape Design Sensitivity Analysis in Shape Optimization Problems and its Application)

  • 곽현구;최주호
    • 한국전산구조공학회논문집
    • /
    • 제18권3호
    • /
    • pp.255-263
    • /
    • 2005
  • 본 논문에서는 다양한 문제들의 형상 설계 민감도 해석에 대한 효율적인 경계기반 기법을 제시하였다 우선 문제에서 정의된 일반적인 함수들에 대한 연속체 형태의 식에 근거하여, 경계 적분 형태의 해석적 민감도 식을 유도하였다. 이 식은 다양한 형상 설계 문제들의 경사를 계산하는데 편리하게 사용할 수 있다. 그리고 경계법은 형상 변분 벡터가 전체 도메인이 아닌 경계에서만 요구된다는 장점이 있는데, 여기서 경계 형상 변분은 형상 함수의 복잡한 해석적 미분 대신 형상을 미소 증분시킴으로써 편리하게 계산할 수 있다. 제시한 방법의 효율성을 보이기 위해 포텐셜 유동 문제와 필렛(fillet)에서의 응력 집중 문제에 이를 적용하였다.

Shape Design Sensitivity Analysis for Interface Problem in Axisymmetric Elasticity

  • Choi, Joo-Ho;Lee, Boo-Youn;Han, Jung-Suk
    • Journal of Mechanical Science and Technology
    • /
    • 제14권2호
    • /
    • pp.197-206
    • /
    • 2000
  • A boundary integral equation method in the shape design sensitivity analysis is developed for the elasticity problems with axisymmetric non-homogeneous bodies. Functionals involving displacements and tractions at the zonal interface are considered. Sensitivity formula in terms of the interface shape variation is then derived by taking derivative of the boundary integral identity. Adjoint problem is defined such that displacement and traction discontinuity is imposed at the interface. Analytic example for a compound cylinder is taken to show the validity of the derived sensitivity formula. In the numerical implementation, solutions at the interface for the primal and adjoint system are used for the sensitivity. While the BEM is a natural tool for the solution, more generalization should be made since it should handle the jump conditions at the interface. Accuracy of the sensitivity is evaluated numerically by the same compound cylinder problem. The endosseous implant-bone interface problem is considered next as a practical application, in which the stress value is of great importance for successful osseointegration at the interface. As a preliminary step, a simple model with tapered cylinder is considered in this paper. Numerical accuracy is shown to be excellent which promises that the method can be used as an efficient and reliable tool in the optimization procedure for the implant design. Though only the axisymmetric problem is considered here, the method can be applied to general elasticity problems having interface.

  • PDF

민들린 평판의 아이소-지오메트릭 형상 설계민감도 해석 (Isogeometric Shape Design Sensitivity Analysis of Mindlin Plates)

  • 이승욱;조선호
    • 한국전산구조공학회논문집
    • /
    • 제26권4호
    • /
    • pp.255-262
    • /
    • 2013
  • 본 논문에서는 아이소-지오메트릭 기법을 기반으로 민들린 후판에 대한 형상 설계민감도 해석법을 제시하였다. 아이소-지오메트릭 기법은 정확한 기하학적 형상의 표현, 요소 사이의 높은 연속성 등 바람직한 강점들을 가지고 있으며 궁극적으로는 해석해로의 빠른 수렴성과 정확한 설계민감도를 제공한다. 선형 형상함수를 사용하는 유한요소법과는 달리 아이소-지오메트릭 기법에서는 높은 차수의 NURBS 기저함수를 활용하여 CAD 형상의 법선벡터와 곡률을 정확하게 고려한다. 전단 잠김(Shear locking) 현상을 극복하기 위해서 선택적 감소적분(Selective reduced integration) 기법을 사용하였다. 이 간단한 방법은 복잡한 정식화 과정 없이 정확한 아이소-지오메트릭 형상 설계민감도 해석을 수행한다. 굽힘 문제에 대한 수치예제를 통하여 제안된 아이소-지오메트릭 해석과 유한요소 해석을 비교하였으며, 유한차분 설계민감도와 비교하여 아이소-지오메트릭 형상 설계민감도는 매우 정확함을 확인하였다.

Sensitivity and optimisation procedures for truss structures under large displacement

  • Bothma, A.S.;Ronda, J.;Kleiber, M.
    • Structural Engineering and Mechanics
    • /
    • 제7권1호
    • /
    • pp.111-126
    • /
    • 1999
  • The work presented here focuses on the development of suitable discretised formulations, for large-displacement shape and non-shape design sensitivity analysis (DSA), which enable the straightforward incorporation of structural optimisation into established finite element analysis (FEA) codes. For the generalised displacement-based functional the design sensitivity vector has been expressed in terms of displacement sensitivity. The Total Lagrangian formulation is utilised for modelling of large deformation of truss structures. The variational formulation of the sensitivity analysis procedure is discretised by using "pseudo" - finite elements, Results are presented for the sensitivity analysis and optimisation of standard truss structures. For the purposes of this work, the analysis and optimisation procedures outlined below are incorporated into the FEA code ABAQUS.

민감도기법과 RSM을 이용한 대용량 BLDC 전동기 영구자석의 형상 최적화 (A Magnet Pole Shape Optimization of a Large Scale BLDC Motor Using a RSM With Design Sensitivity Analysis)

  • 신판석;정현구;우성현
    • 전기학회논문지
    • /
    • 제58권4호
    • /
    • pp.735-741
    • /
    • 2009
  • This paper presents an algorithm for the permanent magnet shape optimization of a large scale BLDC(Brushless DC) motor to minimize the cogging torque. A response surface method (RSM) using multiquadric radial basis function is employed to interpolate the objective function in design parameter space. In order to get a reasonable response surface with relatively small number of sampling data points, additional sampling points are added on the basis of design sensitivity analysis computed by using FEM. The algorithm has 2 stages: the first stage is to determine the PM arc angle, and the 2nd stage is to optimize the magnet pole shape. The developed algorithm is applied to a 5MW BLDC motor to get a minimum cogging torque. After 3 iterations with 4 design parameters, the cogging torque is reduced to 13.2% of the initial one.

Boundary Method for Shape Design Sensitivity Analysis in Solving Free-Surface Flow Problems

  • Choi Joo Ho;Kwak H. G.;Grandhi R. V.
    • Journal of Mechanical Science and Technology
    • /
    • 제19권12호
    • /
    • pp.2231-2244
    • /
    • 2005
  • An efficient boundary-based optimization technique is applied in the numerical computation of free surface flow problems, by reformulating them into the equivalent optimal shape design problems. While the sensitivity in the boundary method has mainly been calculated using the boundary element method (BEM) as an analysis means, the finite element method (FEM) is used in this study because of its popularity and easy-to-use features. The advantage of boundary method is that the design velocity vectors are needed only on the boundary, not over the whole domain. As such, a determination of the complicated domain design velocity field, which is necessary in the domain method, is eliminated, thereby making the process easy to implement and efficient. Seepage and supercavitating flow problem are chosen to illustrate the accuracy and effectiveness of the proposed method.

설계민감도 해석을 이용한 정전소자의 형상최적화 (OPTIMAL SHAPE DESIGN OF ELECTROSTATIC DEVICES USING DESIGN SENSITIVITY ANALYSIS)

  • 고창섭;정현교;한송엽
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 1991년도 하계학술대회 논문집
    • /
    • pp.93-96
    • /
    • 1991
  • This paper describes a new algorithm based on design sensitivity analysis for optimal shape design of electrostatic devices. The design sensitivity, the variation of the object function with respect to the design variables, is derived by using implicit differentiation and direct boundary element methods. The proposed algorithm is applied to the optimal shape design of a concentric cable and the rod electrode enclosed by earthed case, It is shown, from the numerical results, that the algorithm is very usefull for the optimal shape design of the electrostatic devices.

  • PDF