• Title/Summary/Keyword: Topology Optimization Method

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Development of a Material Mixing Method for Topology Optimization of PCB Substrate (PCB판의 위상 최적화를 위한 재료혼합법의 개발)

  • Han, Seog-Young;Kim, Min-Sue;Hwang, Joon-Sung;Choi, Sang-Hyuk;Park, Jae-Yong;Lee, Byung-Ju
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.16 no.1
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    • pp.47-52
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    • 2007
  • A material mixing method to obtain an optimal topology for a structure in a thermal environment was suggested. This method is based on Evolutionary Structural Optimization(ESO). The proposed material mixing method extends the ESO method to a mixing several materials for a structure in the multicriteria optimization of thermal flux and thermal stress. To do this, the multiobjective optimization technique was implemented. The overall efficiency of material usage was measured in terms of the combination of thermal stress levels and heat flux densities by using a combination strategy with weighting factors. Also, a smoothing scheme was implemented to suppress the checkerboard pattern in the procedure of topology optimization. It is concluded that ESO method with a smoothing scheme is effectively applied to topology optimization. Optimal topologies having multiple thermal criteria for a printed circuit board(PCB) substrate were presented to illustrate validity of the suggested material mixing method. It was found that the suggested method works very well for the multicriteria topology optimization.

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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    • 2000.06a
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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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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.

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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Topology Optimization of Continuum Structures Using a Nodal Volume Fraction Method

  • Lee, Jin-Sik;Lim, O-Kaung
    • Computational Structural Engineering : An International Journal
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    • v.1 no.1
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    • pp.21-29
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    • 2001
  • The general topology optimization can be considered as optimal material distribution. Such an approach can be unstable, unless composite materials are introduced. In this research, a nodal volume fraction method is used to obtain the optimum topology of continuum structures. This method is conducted from a composite material model composed of isotropic matter and spherical void. Because the appearance of the chessboard patterns makes the interpretation of the optimal material layout very difficult, this method contains a chessboard prevention strategy. In this research, several topology optimization problems are presented to demonstrate the validity of the present method and the recursive quadratic programming algorithm is used to solve the topology optimization problems.

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Topology Optimization of Connection Component System Using Density Distribution Method (밀도분포법을 이용한 부재의 연결구조 최적화)

  • 한석영;유재원
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.4
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    • pp.50-56
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    • 2003
  • Most engineering products contain more than one component. Failure occurs either at the connection itself or in the component at the point of attachment of the connection in many engineering structures. The allocation and design of connections such as bolts, spot-welds, adhesive etc. usually play an important role in the structure of multi-components. Topology optimization of connection component provides more practical solution in design of multi-component connection system. In this study, a topology optimization based on density distribution approach has been applied to optimal location of fasteners such as T-shape, L-shape and multi-component connection system. From the results, it was verified that the number of iteration was reduced, and the optimal topology was obtained very similarly comparing with ESO method. Therefore, it can be concluded that the density distribution method is very suitable for topology optimization of multi-component structures.

An Analysis of Femoral Bone Remodeling Using Topology Optimization Method

  • Choi J. B.
    • Journal of Biomedical Engineering Research
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    • v.26 no.6
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    • pp.365-372
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    • 2005
  • Topology optimization method has a great advantage and capability over a conventional shape optimization technique because it optimizes a topology as well as a shape and size of structure. The purpose of the present study, using topology optimization method with an objective function of minimum compliance as a mechanism of bone remodeling, is to examine which shape factors of femur is strongly related with the curvature of femoral shaft. As is expected, the optimized curvature increased definitely with neck angle among the shape factors and showed a similar trend with the measured curvature to neck angle. Therefore, the topology optimization method can be successfully applied in the analysis of bone remodeling phenomenon in the subsequent studies.

A Study on Topology Optimization of Table Liner for Vertical Roller Mill using Homogenization Method (균질화법을 이용한 수직형 롤러 분쇄기용 테이블 라이너의 위상최적설계에 관한 연구)

  • 이동우;홍순혁;조석수;이선봉;주원식
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.6
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    • pp.113-122
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    • 2003
  • Topology optimization is begun with layout optimization that is attributed to Rozvany and Prager of the 1960's. They claimed that structure was transformed into truss connecting all the nodes of finite element and optimized by control of its sectional modulus. But, this method is partial topology optimization. General layout optimal design appliable to continum structure was proposed by Bendsoe and Kikuchi in 1988. Topology optimization expresses material stiffness of structure into function of arbitrary variable. If this variable is 1, material exists but if this variable is 0, material doesn't exist. Therefore, topology optimization searches the distribution function of material stiffness for structure. There are a few researchs for simple engineering problem such as topology optimization of square plane structure or truss structure. So, This study applied to topology optimization of table liner for vertical roller mill that is the largest scale in the world. After table liner decreased by 20% of original weight, the structure analysis for first optimized model was performed.

Design Sensitivity Analysis and Topology Optimization Method for Power Flow Analysis at High Frequency (고주파수대역에서 파워흐름해석법을 이용한 구조물의 설계민감도 해석과 위상최적설계)

  • 박찬영;박영호;조선호;홍석윤
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2004.04a
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    • pp.119-126
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    • 2004
  • A continuum-based design sensitivity analysis and topology optimization methods are developed for power flow analysis. Efficient adjoint sensitivity analysis method is employed and further extended to topology optimization problems. Young's moduli of all the finite elements are selected as design variables and parameterized using a bulk material density function. The objective function and constraint are an energy compliance of the system and an allowable volume fraction, respectively. A gradient-based optimization, the modified method of feasible direction, is used to obtain the optimal material layout. Through several numerical examples, we notice that the developed design sensitivity analysis method is very accurate and efficient compared with the finite difference sensitivity. Also, the topology optimization method provides physically meaningful results. The developed is design sensitivity analysis method is very useful to systematically predict the impact on the design variations. Furthermore, the topology optimization method can be utilized in the layout design of structural systems.

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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.