• Title, Summary, Keyword: Topology Optimization

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Magnet Design using Topology Optimization

  • Jenam Kang;Park, Seungkyu;Semyung Wang
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • v.3B no.2
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    • pp.79-83
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    • 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.

Topology Optimization of Shell Structures Using Adaptive Inner-Front Level Set Method (AIFLSM) (적응적 내부 경계를 갖는 레벨셋 방법을 이용한 쉘 구조물의 위상최적설계)

  • Park, Kang-Soo;Youn, Sung-Kie
    • Proceedings of the KSME Conference
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    • pp.354-359
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    • 2007
  • A new level set based topology optimization employing inner-front creation algorithm is presented. In the conventional level set based topology optimization, the optimum topology strongly depends on the initial level set distribution due to the incapability of inner-front creation during optimization process. In the present work, an inner-front creation algorithm is proposed, in which the sizes, positions, and number of new inner-fronts during the optimization process can be globally and consistently identified. To update the level set function during the optimization process, the least-squares finite element method is employed. As demonstrative examples for the flexibility and usefulness of the proposed method, the level set based topology optimization considering lightweight design of 3D shell structure is carried out.

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Sequential Design of Experiment Based Topology Optimization (순차적 실험계획법을 이용한 위상 최적 설계)

  • Song, Chi-Oh;Park, Soon-Ok;Yoo, Jeong-Hoon
    • Transactions of the Society of Information Storage Systems
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    • v.3 no.4
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    • pp.178-182
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    • 2007
  • Topology optimization methods are classified into two methods such as the density method and the homogenization method. Those methods need to consider relationships between the material property and the density of each element in a design domain, the relaxation of the design space, etc. However, it is hard to apply on some cases due to the complexity to compose the design objective and its sensitivity analysis. In this paper, a modified topology optimization is proposed to assist designers who do not have mathematical or theoretical background of the topology optimization. In this study, optimal topology of structures can be achieved by the sequential design of experiment (DOE) and the sensitivity analysis. We conducted the DOE with an orthogonal array and the sensitivity analysis of design variables to determine sensitive variables used for connectivity between elements. The modified topology optimization method has advantages such as freedom from penalizing intermediate values and easy application with basic DOE concept.

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Hybrid of topological derivative-based level set method and isogeometric analysis for structural topology optimization

  • Roodsarabi, Mehdi;Khatibinia, Mohsen;Sarafrazi, Seyyed R.
    • Steel and Composite Structures
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    • v.21 no.6
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    • pp.1389-1410
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    • 2016
  • This paper proposes a hybrid of topological derivative-based level set method (LSM) and isogeometric analysis (IGA) for structural topology optimization. In topology optimization a significant drawback of the conventional LSM is that it cannot create new holes in the design domain. In this study, the topological derivative approach is used to create new holes in appropriate places of the design domain, and alleviate the strong dependency of the optimal topology on the initial design. Furthermore, the values of the gradient vector in Hamilton-Jacobi equation in the conventional LSM are replaced with a Delta function. In the topology optimization procedure IGA based on Non-Uniform Rational B-Spline (NURBS) functions is utilized to overcome the drawbacks in the conventional finite element method (FEM) based topology optimization approaches. Several numerical examples are provided to confirm the computational efficiency and robustness of the proposed method in comparison with derivative-based LSM and FEM.

Topology Decision of Truss Structures by Advanced Evolutionary Structural Optimization Method (개선된 진화론적 구조최적화에 의한 트러스 구조물의 형태결정)

  • Jeong, Se-Hyung;Pyeon, Hae-Wan
    • Journal of the Korean Association for Spatial Structures
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    • v.3 no.3
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    • pp.67-74
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    • 2003
  • The purpose of this study is to improve convergence speed of topology optimization procedure using the existing ESO method and to deal with topology decision of the truss structures according to a boundary condition, such as cantilever type. At the existing ESO topology optimization procedure for the truss structures, the adjustment of member sizes according to target stress has been executed by increasing or reducing a very small value from each member size. In this case, it takes too much iteration till convergence. Accordingly, it is practically hard to obtain optimum topology for a large scale structures. For that reason, it is necessary to improve convergence speed of ESO method more effectively. During the topology decision procedure, member sizes are adjusted by calculating approximate solution for member sizes corresponding to the target stress at every step, the new member sizes are adjusted by such method are applied in FEA procedure of next step.

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Topology optimization of the structure using multimaterial inclusions

  • Kutylowski, Ryszard
    • Structural Engineering and Mechanics
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    • v.33 no.3
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    • pp.285-306
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    • 2009
  • In the literature the problem of the topology optimization of the structure is usually solved for one, clearly described from the mechanical point of view material. Generally the topology optimization answers the question of the distribution of this mentioned above material within the design domain. Finally, material-voids distribution it is obtained. In this paper, for the structure mainly strengthened or sometimes weakened by the inclusions, the variation approach of the topology optimization problem is formulated. This multi material approach may be useful for the design process of various mechanical or civil engineering structures which need to be more "refined" and more "optimal" than they can be using previous topology optimization procedures of optimization one material structures.

Generation of OC and MMA topology optimizer by using accelerating design variables

  • Lee, Dongkyu;Nguyen, Hong Chan;Shin, Soomi
    • Structural Engineering and Mechanics
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    • v.55 no.5
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    • pp.901-911
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    • 2015
  • The goal of this study is to investigate computational convergence of optimal solutions, with respect to optimality criteria (OC) method and methods of moving asymptotes (MMA) as optimization model for non-linear programming of material topology optimization using an acceleration method that makes design variables rapidly move toward almost 0 and 1 values. 99 line topology optimization MATLAB code uses loop vectorization and memory pre-allocation as properly exploiting the strengths of MATLAB and moves portions of code out of the optimization loop so that they are only executed once as restructuring the program. Numerical examples of a simple beam under a lateral load and a given material density limitation provide merits and demerits of the present OC and MMA for 99 line topology optimization code of continuous material topology optimization design.

Topology Optimization of the Primary Mirror of a Multi-Spectral Camera (인공위성 카메라 주반사경의 위상최적화)

  • Park, Kang-Soo;Chang, Su-Young;Lee, Eung-Shik;Youn, Sung-Kie
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.6
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    • pp.1194-1202
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    • 2002
  • A study on the topology optimization of a multi-spectral camera for space-use is presented. The optimization is carried out under self-weight and polishing pressure loading. A multi-spectral camera for space-use experiences degradation of optical image in the space, which can not be detected on the optical test bench on the earth. An optical surface deformation of a primary mirror, which is a principal component of the camera system, is an important factor affecting the optical performance of the whole camera system. In this study, topology optimization of the primary mirror of the camera is presented. As an objective function, a measure of Strehl ratio is used. Total mass of the primary mirror is given as a constraint to the optimization problem. The sensitivities of the objective function and constraint are calculated by direct differentiation method. Optimization procedure is carried out by an optimality criteria method. For the light-weight primary mirror design, a three dimensional model is treated. As a preliminary example, topology optimization considering a self-weight loading is treated. In the second example, the polishing pressure is also included as a loading in the topology optimization of the mirror. Results of the optimized design topology for the mirror with various mass constraints are presented.

CAD Model Construction Using Topology Optimization (위상최적설계를 이용한 CAD모델 구축)

  • Lee, Dong-hoon
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.355.1-355
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    • 2002
  • Topology optimization is widely accepted as a conceptual design tool for the product design. Since the resulted layout of the topology optimization is a kind of digital images represented by the density distribution, the seamless process is required to transform digital images to the CAD model for the practical use. In this paper, the general process to construct a CAD model is developed to apply for topology images based on elements. (omitted)

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Topology Optimization of Pick-up Actuator of CD-ROM for Vibration Reduction (위상 최적 설계를 통한 CD-ROM 광 픽업 액추에이터의 진동 저감)

  • Wang, Se-Myung;Kim, Yong-Su;Park, Ky-Hwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.479-484
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    • 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.

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