• Title/Summary/Keyword: Thick Composite Laminates

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Stacking method of thick composite laminates considering interlaminar normal stresses (층간수직응력을 고려한 두꺼운 복합적층판의 적층방법)

  • 김동민;홍창선
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.12 no.5
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    • pp.944-951
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    • 1988
  • Global-Local Laminate Variational Model is utilized to investigate the characteristics of interlaminar stresses in thick composite laminates under uniform axial extension. Various laminates with different fiber orientation and stacking sequences are analyzed to observe the behavior of interlaminar normal stresses. From this result, the interlaminar normal stress distribution along the laminate interfaces is examined and discussed with an existing approximation model. The repeated stacking of Poisson's ratio symmetric sublaminates is found to be the best stacking method of thick composite laminates to reduce the interlaminar normal stresses for the prevention of the free-edge delamination.

Cure simulation and Consolidation for a Thick Glass/Epoxy Laminate (유리섬유/에폭시 후판 복합재료의 경화공정 및 압밀해석)

  • O, Je-Hun;Lee, Dae-Gil
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.11
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    • pp.2853-2865
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    • 2000
  • During the curing process of thick glass/epoxy laminates, a substantial amount of temperature lag and overshoot at the center of the laminates is usually experienced due to the large thickness and low thermal conductivity of the glass/epoxy composites. Also, it takes a longer time for full and uniform consolidation. In this work, temperature, degree of cure and consolidation of a 20 mm thick unidirectional glass/epoxy laminate were investigated using an experiment and a 3-dimentional numerical analysis. From the experimental and numerical results, it was found that the experimentally obtained temperature profile agreed well with the numerical one, and the cure cycle recommended by the prepreg manufacturer should be modified to prevent a temperature overshoot and to obtain full consolidation.

Thermal Stress Analysis of Composite Beam through Dimension Reduction and Recovery Relation (차원축소와 복원관계를 통한 복합재료 보의 열응력 해석)

  • Jang, Jun Hwan;Ahn, Sang Ho
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.30 no.5
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    • pp.381-387
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    • 2017
  • Fiber-reinforced composites not only have a direction of thermal expansion coefficient, but also inevitably suffer thermal stress effects due to the difference between the manufacturing process temperature and the actual use temperature. The damage caused by thermal stress is more prominent in the case of thick composite laminates, which are increasingly applied in the aerospace industry, and have a great influence on the mechanical function and fracture strength of the laminates. In this study, the dimensional reduction and thermal stress recovery theory of composite beam structure having high slenderness ratio is introduced and show the efficiency and accuracy of the thermal stress comparison results between the 3-D finite element model and the dimension reduction beam model. Efficient recovery analysis study will be introduced by reconstructing the thermal stress of the composite beam section applied to the thermal environment by constructing the dimensional reduction modeling and recovery relations.