• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.726-728
• /
• 2002

The topology optimization of electromagnetic systems with two materials is investigated using the FEM. The design sensitivity equation for topology optimization is derived using the adjoint variable method and the continuum approach. The proposed method is applied to the topology optimization of C-core and compared to previous study with one material.

• Proceedings of the KIEE Conference
• /
• 1986.07a
• /
• pp.140-144
• /
• 1986

In this paper an FIR(finite impulse response) filter and smoother are introduced for discrete time-invariant state-space models with driving noises. The FIR structure not only quarantees the BIBO stability and the robustness to parameter changes but also improves the filter divergence problem. It is shown that the impulse responses of the FIR filter and the smoother are obtained by Riccati-type difference equations and that they are to be time-invariant and reduced to very simple forms. For implementational purpose, recursive forms of the FIR filler and smoother are derived with each other used as the adjoint variable.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2005.04a
• /
• pp.309-316
• /
• 2005

In this paper, we develop continuum-based design sensitivity analysis (DSA) methods using both direct differential method (DDM) and adjoint variable method (AVM) for non-shape design problems. The developed DSA method is further utilized for the topology design optimization of 3-dimensional structures. In numerical examples, the analytical DSA results are verified using finite difference ones. The topology optimization method yields very reasonable results in physical point of view.

• Proceedings of the KIEE Conference
• /
• 2011.07a
• /
• pp.872-873
• /
• 2011

This paper presents a multi-domain topology optimization using the harmonically excited coil and the iron in order to focus pulsed magnetic field (PMF). The design sensitivity of the harmonic magnetic field is derived by adjoint variable method. As a result of the optimization, PMF is considerably concentrated on the objective domain with much less leakage than the initial model.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.9 no.1
• /
• pp.119-126
• /
• 1985

형상은 3차원이지만 2차원 문제로 이상화하여 해석할 수 있는 탄성구조물의 최적설계를 내연기관 연결봉(Connecting Rod)을 예제로 사용하여 진행하였다. 연결봉은 각 부위에서의 두께는 다르나 평면응력상태에 있다고 가정하였다. 연결봉의 질량을 최소화하기 위해 두께의 분포 및 2차원 모델 경계의 모양을 설계변수로 채택하였고 설계변수 및 응력치에 대한 제한조건을 적용하였다. 설계감도계수 계산을 위해 Variational Formulation, Material Derivative, Adjoint Variable이론을 도입하였고 최적화 방법으로는 Gradient Projection Method를 사용하였다. 최적설계 결과 현재 사용중인 연결봉 무게의 20%를 줄일 수 있음이 밝혀졌다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.06a
• /
• pp.479-484
• /
• 2000

The topology optimization of electromagnetic systems is investigated and the TOPEM (Topology Optimization for Electromagnetic Systems) is developed using the finite element method (FEM). The design sensitivity equation for topology optimization is derived using the adjoint variable method. The proposed method is validated by applying it to the topology optimizations of a C-core actuator and an optical pickup actuator.

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.655-656
• /
• 2008

This research presents a topology optimization to minimize eddy current loss maintaining mechanical robustness of structure part in electrical machines A design sensitivity equation for the topology optimization is derived by employing the discrete system equations combined with the adjoint variable method. As a numerical example, frame design of a C-core actuator is performed by the proposed method.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
• /
• v.3B no.2
• /
• pp.79-83
• /
• 2003

The topology optimization for the magnet design is studied. The magnet design in the C-core actuator is investigated by using the derived topology optimization algorithm and finite element method. The design sensitivity equation for the topology optimization is derived using the adjoint variable method and the continuum approach.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.705-707
• /
• 2003

The design of multi-domain that considers all components of the electromagnetic systems such as air, iron, magnet, and coil is investigated using the topology optimization, interpolation method, and FEM. The design sensitivity equation for the topology optimization is derived using the adjoint variable method and the continuum approach. The proposed method is applied to the topology optimization of C-core actuator.

• Proceedings of the KIEE Conference
• /
• 2003.07b
• /
• pp.708-710
• /
• 2003

This paper presents design sensitivity analysis for the electromagnetic force and torque obtained from Coulomb's virtual work method using the adjoint variable method. And virtual displacement field is calculated from a static structural analysis. Derived equations are verified by comparison with finite different method. And topology optimization for a c-core is given as a verification example.