• 제목/요약/키워드: Shape Optimization

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유한요소해석과 기하학적 모델링의 연동에 기초한 쉘 곡면의 형상 최적 설계 (Shape Optimization of Shell Surfaces Based on Linkage Framework betweenGeometric Modeling and Finite Element Analysis)

  • 김현철;노희열;조맹효
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 추계학술대회
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    • pp.1328-1333
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    • 2003
  • In the present study, an integrated framework of geometric modeling, analysis, and design optimization is proposed. Geometric modeling is based on B-spline surface representation. Geometrically-exact shell finite element is implemented in analysis module. Control points of the surface are selected as design variables for optimization, which can make the interaction easier between analysis and surface representation. Sequential linear programming(SLP) is adopted for the shape optimization of surfaces. For the computation of shape sensitivities, semi-analytical method is used. The developed integrated framework should serve as a powerful tool for the geometric modeling, analysis, and shape design of surfaces.

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부드러운 경계 위상 최적설계기법을 이용한 유전체 형상 및 위상 최적설계 (Optimal Design of Dielectric shape and Topology using Smooth Boundary Topology Optimization Method)

  • 정기우;최낙선;김남경;김동훈
    • 전기학회논문지
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    • 제58권10호
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    • pp.1936-1941
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    • 2009
  • This paper deals with a new methodology for topology optimization in which the topology of the design domain may change during the shape optimization process. To achieve this, the concept of the topological gradient is introduced to compute the sensitivity of an objective function when a small hole is drilled in the domain. Based on shape and topological sensitivity values, the shape and topology of the design domain may be simultaneously changed during design iterations if necessary. To verify the advantages and also to facilitate understanding of the method itself, two electrostatic design problems have been tested by using 2D finite element analysis: the first is the inverse problem of a simple dielectric model and the second is the rotor design of a MEMS actuator.

초공동(超空洞) 하의 수중 주행체 캐비테이터 형상최적설계 (Shape Optimization of Cavitator for a Supercavitating Projectile Underwater)

  • 최주호
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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    • pp.82-85
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    • 2008
  • 수중에서 발사체가 고속으로 주행할 때 발사체의 머리 즉, 캐비테이터 만이 물과 접촉한 상태에서 커다란 공동이 발생하여 몸체 전체를 뒤덮는 초공동현상이 발생한다. 초공동 상태에서는 발사체는 저항이 감소되어 매우 빠른 속도를 낼 수 있게 된다. 더욱이 캐비테이터가 적합한 형상을 가지게 되면 매우 낮은 압력저항을 유지하고 전체적인 저항도 획기적으로 줄일 수 있기 때문에 본 연구에서는 주어진 작용환경 하에서 저항을 최소화 하기위한 최적의 캐비테이터 형상최적설계 문제를 고려하였다. 그리고 효율적인 캐비테이터 형상최적화를 위해 공동과 캐비테이터 형상을 하나의 죄적화로 변환한 동시최적화기법을 수행하였다.

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Performance study of a simplified shape optimization strategy for blended-wing-body underwater gliders

  • Li, Chengshan;Wang, Peng;Li, Tianbo;Dong, Huachao
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제12권1호
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    • pp.455-467
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    • 2020
  • Shape design optimization for Blended-wing-body Underwater Gliders (BWBUGs) is usually computationally expensive. In our previous work, a simplified shape optimization (SSO) strategy is proposed to alleviate the computational burden, which optimizes some of the Sectional Airfoils (SAs) instead of optimizing the 3-D shape of the BWBUG directly. Test results show that SSO can obtain a good result at a much smaller computational cost when three SAs are adopted. In this paper, the performance of SSO is investigated with a different number of SAs selected from the BWBUG, and the results are compared with that of the Direct Shape Optimization (DSO) strategy. Results indicate that SSO tends to perform better with more SAs or even outperforms the DSO strategy in some cases, and the amount of saved computational cost also increases when more SAs are adopted, which provides some reference significance and enlarges the applicability range of SSO.

최적화 방법에 따른 축류압축기의 효율평가 (Evaluation of Efficiency by Applying Different Optimization Method for Axial Compressor)

  • 장춘만;;김광용
    • 유체기계공업학회:학술대회논문집
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    • 유체기계공업학회 2006년 제4회 한국유체공학학술대회 논문집
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    • pp.543-544
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    • 2006
  • Shape optimization of a transonic axial compressor rotor operating at the design flow condition has been performed using three-dimensional Navier-Stokes analysis and three different surrogate models: i.e.., Response Surface Method(RSM), Kriging Method, and Radial Basis Function(RBF). Three design variables of blade sweep, lean and skew are introduced to optimize the three-dimensional stacking line of the rotor blade. The object function of the shape optimization is selected as an adiabatic efficiency. Throughout the shape optimization of the rotor blade, the adiabatic efficiency is increased for the three different surrogate models. Detailed flow characteristics at the optimal blade shape obtained by different optimization method are drawn and discussed.

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유전 알고리즘을 이용한 공력 형상 최적화 연구 (Study of Aerodynamic Design Optimization Using Genetic Algorithm)

  • 김수환;권장혁
    • 한국전산유체공학회지
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    • 제6권3호
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    • pp.10-18
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    • 2001
  • Genetic Algorithm(GA) is applied to aerodynamic shape optimization and demonstrated its merits in global searching ability and the independency of differentiability. However, applications of GA are limited due to slow convergence rate, premature termination, and high computing costs. The present aerodynamic designs such as wing shape optimizations using GA have seldom been applied because of high computing costs. This paper has two objects; improvement of the efficiency of GA and application of GA into aerodynamic shape optimization for 2D and 3D wings. The study indicates that GA can be applied to aerodynamic design and its performance is comparable to traditional design methods.

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Parametric Modeling and Shape Optimization of Offshore Structures

  • Birk, Lothar
    • International Journal of CAD/CAM
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    • 제6권1호
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    • pp.29-40
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    • 2006
  • The paper presents an optimization system which integrates a parametric design tool, 3D diffraction-radiation analysis and hydrodynamic performance assessment based on short and long term wave statistics. Controlled by formal optimization strategies the system is able to design offshore structure hulls with superior seakeeping qualities. The parametric modeling tool enables the designer to specify the geometric characteristics of the design from displacement over principal dimensions down to local shape properties. The computer generates the hull form and passes it on to the hydrodynamic analysis, which computes response amplitude operators (RAOs) for forces and motions. Combining the RAOs with short and long-term wave statistics provides a realistic assessment of the quality of the design. The optimization algorithm changes selected shape parameters in order to minimize forces and motions, thus increasing availability and safety of the system. Constraints ensure that only feasible designs with sufficient stability in operation and survival condition are generated. As an example the optimization study of a semisubmersible is discussed. It illustrates how offshore structures can be optimized for a specific target area of operation.

Trust Region 기법을 이용한 공력 형상 최적설계 (The Aerodynamic Shape Optimization with Trust Region Methods)

  • 이재훈;정경진;권장혁
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.130-133
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    • 2008
  • In this paper the trust region method is studied and applied in aerodynamic shape optimization. The trust region method is a gradient-based optimization method, but it is not as popular as other methods in engineering computations. Its theory will be explained for unconstrained optimization problems and a trust region subproblem will be solved with the dogleg method. After verifying the trust region method with analytical test problems, it is applied to aerodynamic shape design optimization and the performance of airfoil is improved successfully.

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An Analysis of Femoral Bone Remodeling Using Topology Optimization Method

  • Choi J. B.
    • 대한의용생체공학회:의공학회지
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    • 제26권6호
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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.

Shape and size optimization of trusses with dynamic constraints using a metaheuristic algorithm

  • Grzywinski, Maksym;Selejdak, Jacek;Dede, Tayfun
    • Steel and Composite Structures
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    • 제33권5호
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    • pp.747-753
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    • 2019
  • Metaheuristic algorithm is used to solve the weight minimization problem of truss structures considering shape, and sizing design variables. The cross-sectional areas of the line element in trusses are the design variables for size optimization and the changeable joint coordinates are the shape optimization used in this study. The design of plane and spatial truss structures are optimized by metaheuristic technique named Teaching-Learning-Based Optimization (TLBO). Finite element analyses of structures and optimization process are carried out by the computer program visually developed by the authors coded in MATLAB. The four benchmark problems (trusses 2D ten-bar, 3D thirty-seven-bar, 3D seventy-two-bar and 2D two-hundred-bar) taken from literature are optimized and the optimal solution compared the results given by previous studies.