• Title, Summary, Keyword: 기능경사 내열복합재

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Thermo-Elastoplastic Analysis of Ni/Al$_2$O$_3$Heat-Resisting Functionally Graded Composites (Ni/Al$_2$O$_3$기능경사 내열복합재의 열-탄소성 해석)

  • 조진래;김병국;하대율
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.1
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    • pp.11-19
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    • 2001
  • 기능경사재(FGM)는 구성 물질의 체적분율(volume fraction)이 복합재 전체에 걸쳐 연속적 그리고 기능적으로 분포되어 있어, 기존의 이종물질 접합식(bi-material-type) 복합재보다 현저히 우수한 열기계적 특성을 가진다. 하지만, 기능경사 내열복합재의 열-탄소성 거동은 체적분율의 분포형태와 경사층이 차지하는 상대두께비에 따라 절대적으로 좌우된다. 본 연구는 기능경사 내열복합재의 열-탄소성 특성의 이들 두 설계인자에 대한 파라메트릭 FEM해석을 다룬 것이다. 열-탄소성 이론과 유한요소 근사화에 따라 연구용 2차원 FEM 프로그램을 개발하고, 대표적인 3층 구조의 2차원 기능경사 내열복합재의 열-탄소성 특성을 설계변수의 다양한 조합에 따라 분석하였다.

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Material Topology Optimization of FGMs using Homogenization and Linear Interpolation Methods (균질화 및 선형보간법을 이용한 기능경사 내열복합재의 물성분포 최적설계)

  • 조진래;박형종
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.4
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    • pp.495-503
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    • 2001
  • In a functionally graded materials(FGM), two constituent material particles are mixed up according to a specific volume fraction distribution so that its thermoelastic behavior is definitely characterized by such a material composition distribution. Therefore, the designer should determine the most suitable volume fraction distribution in order to design a FGM that optimally meets the desired performance against the given constraints. In this paper, we address a numerical optimization procedure, with employing interior penalty function method(IPFM) and FDM, for optimizing 2D volume fractions of heat-resisting FGMs composed of metal and ceramic. We discretize a FGM domain into finite number of homogenized rectangular cells of single design variable in order for the optimization efficiency. However, after the optimization process, we interpolate the discontinuous volume fraction with globally continuous bilinear function in order to enforce the continuity of volume fraction distributions.

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Study on the Volume Fraction Optimization of Functionally Graded Heat-Resisting Composites (기능경사 내열 복합재의 체적분율 최적화에 관한 연구)

  • Jo, Jin-Rae;Ha, Dae-Yul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.6
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    • pp.988-995
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    • 2001
  • Functionally graded materials(FGMs) are highlighted to be suitable for high temperature engineering due to their continuous distribution of material properties. In this paper, an optimal design is executed for determining the optimal material volume distribution pattern that minimizes the steady-state thermal stress of FGM heat-resisting composites. The interior penalty function method and the golden section method are employed as optimization techniques while the finite element method is used for thermal stress analysis. Through numerical simulations we suggest the volume fraction distributions that considerably improve initial thermal stress distributions.