• 제목/요약/키워드: Fiber reinforced plastics plate

검색결과 17건 처리시간 0.019초

보강목질적층판이 사용된 집성재 접합부의 모멘트 저항성능 평가 (Evaluation of The Moment Resistance of Reinforced Wooden Gusset to Glulam Joint)

  • 이인환;송요진;홍순일
    • Journal of the Korean Wood Science and Technology
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    • 제45권1호
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    • pp.53-61
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    • 2017
  • 본 연구에서는 고강성, 고인성의 경량화된 목질접합부를 제작하기 위하여 슬릿 가공된 기둥부재 중앙에 강판 대용인 목질접합물을 삽입하고 기둥부재와 목질접합물만 결합된 시험편들을 제작하였다. 시험편들은 강판을 사용한 대조군 시험편과 모멘트 저항성능을 비교분석하였다. GFRP보강목질적층판과 핀으로 제작된 시험편들은 강판삽입형 시험편 보다 평균 24% 저하된 최대모멘트가 측정되었으나 양호한 인성이 관찰되었다. 파괴형상은 기둥부재의 연단부분에서 연륜을 따라 파괴되었다. 집성재와 목질적층판을 접착제로 일체화한 강절형 시험편은 대조군 시험편보다 초기강성이 2.8배 향상되었고, 최대모멘트도 평균 40% 향상된 경향을 보였다. 강절형 시험편들은 접착층 주위에서 파단되었다.

FRP로 보강된 순환골재 고강도 철근콘크리트 보의 휨거동 (Flexural Behavior of High-Strength Reinforced Concrete Beam with Recycled Aggregate Strengthened by FRP Plate)

  • 홍성욱;이승호;김승훈
    • 한국구조물진단유지관리공학회 논문집
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    • 제22권4호
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    • pp.126-132
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    • 2018
  • 본 연구는 순환골재를 사용한 콘크리트의 활용증대 방안으로 철근콘크리트 구조물의 노후화와 내구성 저하 시 보수 보강으로 사용되는 FRP (AFRP, CFRP) 판으로 보강된 순환골재 고강도콘크리트(40MPa, 60MPa) 보를 제작하여 순환골재 철근콘크리트 보의 휨 보강에 대한 적용성을 평가하고자 한다 기존의 표면매입보강에 따른 에폭시와 FRP 판의 부착력을 고려하지 않기 위해 콘크리트 타설 전 FRP 보강판을 거푸집에 미리 설치하였으며, 순환골재 치환율(30%), 콘크리트 강도(40MPa, 60MPa), 이형철근(D10, D13), FRP 판의 종류(AFRP 판, CFRP 판)를 변수로 12개 실험체를 제작하여, FRP 판과 순환골재 치환율에 따른 휨 성능을 분석하였다. 그 결과 FRP 판으로 보강한 실험체는 무보강 실험체에 비해 최대 17% 증가하는 경향을 나타내었으며 AFRP 판에 비해 CFRP 판의 보강 성능이 우수한 것으로 나타났다. 또한 순환골재 치환율에 따른 보강 성능의 차이는 없는 것으로 나타났다. 실험에 의해 측정된 균열모멘트는 파괴계수를 이용한 결과 기준식과 비슷한 값을 나타났으며 휨 모멘트는 FRP 판을 보강한 일부 시험체가 KCI 2012와 ACI 440-2R에서 제시한 기준을 만족하지 못하는 것으로 나타났다.

강절형 목질접합부의 모멘트저항성능 평가 (Evaluation of Moment Resistance of Rigid Frame with Glued Joint)

  • 이인환;송요진;홍순일
    • Journal of the Korean Wood Science and Technology
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    • 제45권1호
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    • pp.28-35
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    • 2017
  • 본 연구에서는 접합부가 접착제로 일체화된 강절형 기둥-보 접합 시험편과 슬릿 가공한 보부재에 기둥부재와 일체화된 목질접합물을 삽입하고 핀으로 접합한 시험편을 제작하여 모멘트 저항성능을 검토하였다. 목질접합물은 GFRP로 보강한 적층판을 제작하여 사용하였다. 슬릿 가공된 보부재에 GFRP보강적층판을 삽입하고 핀으로 접합된 기둥-보 시험편들은 완전탄소성 모델 분석으로 산출된 특성치들이 대조군인 강판삽입형 기둥-보 시험편보다 20~80% 낮게 측정 되었다. 기둥부재와 보부재가 접착제로 일체화된 강절형 기둥-보 시험편은 초기잔류변형이 거의 관찰되지 않았으며, 강판 삽입형 접합부보다 38% 향상된 초기강성과 41% 향상된 소성률이 측정되었다.

A Study on a Radar Absorbing Structure for Aircraft Leading Edge Application

  • Baek, Sang Min;Lee, Won Jun;Joo, Young Sik
    • International Journal of Aeronautical and Space Sciences
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    • 제18권2호
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    • pp.215-221
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    • 2017
  • An electromagnetic (EM) wave absorber reduces the possibility of radar detection by minimizing the radar cross section (RCS) of structures. In this study, a radar absorbing structure (RAS) was applied to the leading edge of a blended wing body aircraft to reduce RCS in X-band (8.2~12.4GHz) radar. The RAS was composed of a periodic pattern resistive sheet with conductive lossy material and glass-fiber/epoxy composite as a spacer. The applied RAS is a multifunctional composite structure which has both electromagnetic (EM) wave absorbing ability and load-bearing ability. A two dimensional unit absorber was designed first in a flat-plate shape, and then the fabricated leading edge structure incorporating the above RAS was investigated, using simulated and free-space measured reflection loss data from the flat-plate absorber. The leading edge was implemented on the aircraft, and its RCS was measured with respect to various azimuth angles in both polarizations (VV and HH). The RCS reduction effect of the RAS was evaluated in comparison with a leading edge of carbon fabric reinforced plastics (CFRP). The designed leading edge structure was examined through static structural analysis for various aircraft load cases to check structural integrity in terms of margin of safety. The mechanical and structural characteristics of CFRP, RAS and CFRP with RAM structures were also discussed in terms of their weight.

극저온 지지구조물을 위한 CFRP 적층판의 핀 체결부 강도특성 연구 (A Study on the Strength Characteristics of the Pin Jointed CFRP Composites for Cryogenic Supporting Structure)

  • 허남일;김재훈;이영신;김학근;박주식;권면
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2002년도 학술대회 논문집
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    • pp.173-176
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    • 2002
  • Fundamental failure mode in a laminated composite pinned joint is proposed to assess damage resulting from stress concentration in the plate. The joint area is a region with stress concentrations thus a complicated stress state exists. The modeling of damage in a laminated composite pinned joint presents many difficulties because of the complexity of the failure process. In this study, the effect on the bearing strength of the pin jointed Carbon Fiber Reinforced Plastics (CFRP) composites for magnet support structure of KSTAR tokamak with various parameters such as edge distance to diameter, width to diameter, and the temperature of $23^{\circ}C$, $-76^{\circ}C$, and $-196^{\circ}C$ was examined by comparing the experimental results with finite element analysis.

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CFRP 복합재 튜브의 압괴메카니즘에 관한 실험적 연구 (The Experimental Study on the Collapse Mechanism of CFRP Composite Tubes)

  • 김영남;차천석;양인영
    • 한국자동차공학회논문집
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    • 제10권4호
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    • pp.149-157
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    • 2002
  • This paper is to investigate collapse mechanisms of CFRP(Carbon Fiber Reinforced Plastics)composite tubes and to evaluate collapse characteristics on the change of interlaiminar number and ply orientation angle of outer under static and impact axial compression loads. When a CFRP composite tube is crushed, static/impact energy is consumed by friction between the loading plate and the splayed fronds of the tube, by fracture of the fibers, matrix and their interface. These are associated with the energy absorption capability. In general, CFRP tube with 6 interlaminar number(C-type), absorbed more energy than other tubes(A, B, D-types). The maximum collapse load seemed to increase as the interlaminar number of such tubes increases. The collapse mode depended upon orientation angle of outer of CFRP tubes and loading status(static/impact). Typical collapse modes of CFRP tubes are wedge collapse mode, splaying collapse mode and fragmentation collapse mode. The wedge collapse mode was shown in case of CFRP tubes with 0° orientation angle of outer under static and impact loadings. The splaying collapse mode was shown in only case of CFRP tubes with 90°orientation angle of outer under static loadings, however in Impact tests those were collapsed in fragmentation mode .

FRP 어선 보수에 적용되는 겔코트의 해수 침투 방지 효과 (The Prevention Effect of Seawater Penetration of Gel Coat Applied in Repair of FRP Fishing Vessel)

  • 강대곤;박재학
    • 한국안전학회지
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    • 제33권6호
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    • pp.15-21
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    • 2018
  • Ships may collide with reefs or other objects during operation, when arriving or departing ports. The hull plate may be damaged due to the contact with other ships. The total number of domestic powered fishing vessels has decreased, but that of FRP fishing vessels has increased by 0.7% and the ratio of FRP fishing vessels to the total fishing vessels increased to 96%. Recently, fishing vessels has been used as fishing boats for income of non-fishermen as well as fishermen. Therefore, safety management for repair and maintenance is necessary. The penetration of moisture and moisture in the composite material such as FRP may deteriorate the mechanical properties and the salt (NaCl) component of the damaged portion may cause a relatively high deterioration in material strength. The gel coat painting is the final stage of repairs ans maintenance of FRP fishing vessels. The thickness criteria in the domestic and foreign gel coat is 0.3~0.762 mm. The joint specimens, which was immersed in seawater for 120 days, were compared with those without seawater immersion. As a result, the tensile strength was 83 ~ 121.8% and the flexural strength was 83 ~ 113% compared with the specimens without seawater immersion. According to the previous study the tensile strength decreased by more than 29% and the flexural strength decreased by more than 50% when the composite material was immersed in seawater for 1,083 hours without coating. As a result, it was found that the gel coat with 0.5 mm thickness is very effective in preventing the strength decrease of the composite material.