• Title, Summary, Keyword: 노멕스 하니콤

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Microstrip Antenna for SAR Applications with Microwave Composite Laminates and Honeycomb Cores (복합재료 하니콤 샌드위치 판넬을 이용한 SAR 시스템용 마이크로스트립 안테나 개발)

  • 유치상;이라미;황운봉;박현철;박위상
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.195-198
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    • 2000
  • Microstrip antenna for SAR applications is designed with microwave composite laminates and Nomex honeycomb cores, which becomes an aircraft's structural panel. This study demonstrated fabrication, design procedures and structural and electrical performances of complex antenna system presented. For validating structural rigidity, 3-point bending test is performed, and simulation results for the complex antenna array are compared with measurements for its electrical performance. The results show that this antenna system can be applied in dual polarized synthetic aperture radar and has a good flexural stiffness with comparison of previous sandwich constructions.

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Bondline Strength Evaluation of Honeycomb Sandwich Panel For Cure Process and Moisture Absorption (경화공정 및 수분흡수에 따른 복합재료 하니콤 샌드위치 판넬의 접합강도특성 연구)

  • Choe, Heung-Seop;Jeon, Heung-Jae;Nam, Jae-Do
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.1
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    • pp.115-126
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    • 2001
  • In this paper, through a series of comparative experiments, effects of two different cure processing methods, cocure and precure, on the mechanical properties of honeycomb core materials for aircraft applications are considered. Mass of moisture accumulated into the closed cells of the sandwich panel specimen from the measured mass of moisture diffused to the full saturation state into the elements(skin, adhesive layer, Nomex honeycomb), consisting the honeycomb sandwich specimen has been calculated. Water reservoir of 70$\^{C}$ was used to have specimens absorb moisture to see the influence of moisture absorbed into sandwich panel on its mechanical properties. For the repair condition holding for 2 hours at 177$\^{C}$(350℉) temperature, a pressure due to the vapor expansion in each cell of the sandwich panel, which may result in the local separation of the interface between laminated skin and the surface of the honeycomb, has been estimated by vapor pressure-temperature relation from the thermodynamic steam table and compared to the pressure from the ideal gas state equation. The bonding strengths of the laminated skins on the flat surface of the Nomex honeycomb have been compared by the flatwise tension test and climbing drum peel test performed at room temperature for dry, wet and wet-repair specimens, respectively.

Failure of composite sandwich joints under pull-out loading (풀아웃 하중을 받는 복합재 샌드위치 체결부의 파손거동 연구)

  • Park, Yong-Bin;Yang, Hyeon-Jeong;Kweon, Jin-Hwe;Choi, Jin-Ho;Cho, Hyun-Il
    • Composites Research
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    • v.24 no.1
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    • pp.17-23
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    • 2011
  • The failure of composite sandwich joints was experimentally investigated. A total of 30 joint specimens of 5 different types were tested with various fastening methods and core materials. In the NomexTM core sandwich joints, the core shear buckling was commonly observed in all the specimens which was followed by the slope change of the load-displacement curve. After the shear buckling, however, the joints carried additional loads of 50~200% over the buckling loads and then finally failed in the upper face breakage. The joints of PMI foam core showed the shear failure of the core instead of shear buckling and experienced the sharp drop of the carried load. Considering the failure modes, while both the core and face properties are important in the $Nomex^{TM}$ core joints, core shear strength seems to be the critical factor for the foam core joints.

An Investigation on the Strength of Insert Joints of Composite-Honeycomb Sandwich Structures (복합재 -하니콤 샌드위치 구조물의 인써트 조인트 강도 특성 연구)

  • Choi, Ji-Young;Song, Keun-Il;Choi, Jin-Ho;Kim, Kwang-Soo;Jang, Young-Soon;Kweon, Jin-Hwe
    • Composites Research
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    • v.20 no.5
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    • pp.26-33
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    • 2007
  • Pull-out and shear strengths of insert Joints of sandwich structure were investigated by experiment. Specimens were prepared by cocuring of nomex honeycomb core and carbon-epoxy composite face using an adhesive FM73. A total of 75 specimens with 10 different types depending on the core height and density, face thickness, and loading direction were tested. In the test under pull-out loading, although both the core height and density affect the failure loads, the effect of cell density is more serious. Dominant factor fur failure loads of the joints under shear loading is face thickness and the effect of core height is negligible. In the joint with same dimension, failure loads vary depending on the potted area of the core, particularly in the pull-out test.