• Title/Summary/Keyword: Glass epoxy composite

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Investigation of Energy Absorption Property of Glass/Epoxy Composite Tubes with Bevel and Tulip Triggers (베벨 및 튤립 트리거를 갖는 유리섬유 복합소재 튜브의 에너지 흡수특성 평가)

  • Kim, Jung Seok
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.26 no.4
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    • pp.395-401
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    • 2017
  • Energy absorption capabilities and failure modes of circular tubes made of glass/epoxy with two trigger mechanisms were evaluated. Three types of glass/epoxy tubes were fabricated using a hand lay-up method with unidirectional and woven fabric prepregs tapes, and a filament winding method. The one end of the fabricated tubes was machined for the bevel trigger and tulip trigger. Then, crush tests were conducted at 10 mm/min loading speed, wherein the glass/epoxy tubes were crushed by a brittle fracturing mode combined with fragmentation and lamina-splaying modes. The UD glass/epoxy tubes with a bevel trigger and the filament winded tubes with a tulip trigger showed the maximum and minimum specific energy absorptions, respectively, with a difference of 9.3%. The tube with a tulip trigger exhibited a maximum reduction of 5.7% in the initial peak load; the tube with a bevel trigger showed a maximum increase of 2.9% in the specific energy absorption.

Delamination of a composite laminated under monotonic loading

  • Achache, Habib;Benzerdjeb, Abdelouahab;Mehidi, Abdelkader;Boutabout, Benali;Ouinas, Djamel
    • Structural Engineering and Mechanics
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    • v.63 no.5
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    • pp.597-605
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    • 2017
  • Our work aims to analyze using the finite element method the evolution of the stress intensity factor (SIF) parameter K of three laminated folded plates stacks [$+{\alpha}$, $-{\alpha}$], made of the same epoxy matrix and different reinforcement fibers (boron, graphite and glass). Our results show that the angle of orientation of the boron/epoxy composite has no great influence on the variation of the parameter KI. Compared to composite graphite/epoxy and glass/epoxy, the laminated composite boron/epoxy reduces more the SIF KI in the middle of the plate for angles $0^{\circ}{\leq}{\alpha}{\leq}30^{\circ}$.

Permittivities of the E-Glass Fabric/Epoxy Composite Laminates Containing Carbon Black Dispersion (카본 블렉을 함유한 유리섬유 직조 복합재 적층판의 유전율)

  • 김진봉;정재한;김태욱
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2002.10a
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    • pp.56-59
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    • 2002
  • This paper presents a study on the permittivities of the E-glass fabric/epoxy composite laminates containing carbon black dispersions at microwave frequency. Measurement showed that the complex permittivities of the composites depend strongly on the natures and concentrations of the carbon black dispersion. A new scheme to obtain a mixing law for the estimation of complex permittivity is proposed. The experimental values of the complex permittivities were compared to those calculated. Simultaneously, the complex permittivity of carbon black itself was also calculated by the scheme.

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A Study on the Evaluation of Tension-Compression Fatigue Characteristics of Glass Fiber/Epoxy 4-Harness Satin Woven Laminate Composite for the Railway Bogie Application (철도차량 대차 적용 유리섬유/에폭시 4-매 주자직 적층 복합재의 인장-압축 피로특성 평가 연구)

  • Jeon, Kwang-Woo;Shin, Kwang-Bok;Kim, Jung-Seok
    • Composites Research
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    • v.23 no.5
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    • pp.22-29
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    • 2010
  • This paper describes the evaluations of tension-compression fatigue characteristics and life for glass fiber/epoxy laminate composite applied to railway bogie to reduce weight. Test samples of tension-compression fatigue were composed of glass fiber/epoxy 4-harness woven laminate composites with different stacking sequence of warp-direction, fill-direction and ${\pm}45^{\circ}$-direction. The tension-compression fatigue test was conducted with stress ratio (R) of -1 and frequency of 5Hz. Goodman diagram were used to evaluate the fatigue characteristics and life of glass fiber/epoxy 4-harness satin woven laminate composite. Anti-buckling jig was designed to prevent buckling of specimen under compression load. The test results showed that the fatigue characteristics of glass fiber/epoxy 4-harness satin woven laminate composite with stacking sequence of warp-direction had a good performance in comparison with that of SM490 used to conventional metal railway bogie.

AC Insulation Breakdown Properties of the EMNC to Application of Distribution Molded Transformer (배전용 몰드변압기 적용을 위한 EMNC의 교류절연파괴특성 연구)

  • Park, Jae-Jun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.5
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    • pp.649-656
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    • 2013
  • A conventional epoxy-microsilica composite (EMC) and an epoxy-microsilica-nanosilicate composite (EMNC) were prepared in order to apply them to mold-type transformers, current transformers (CT) and potential transformers (PT). Nanosilicate was exfoliated in a epoxy resin using our electric field dispersion process and AC insulation breakdown strength at $30{\sim}150^{\circ}C$, glass transition temperature and viscoelasticity were studied. AC insulation breakdown strength of EMNC was higher than that of EMC and that value of EMNC was far higher at high temperature. Glass transition temperature and viscoelasticity property of EMNC was higher than those of EMC at high temperature. These results was due to the even dispersion of nanosilicates among the nanosilicas, which could be observed using transmission electron microscopy (TEM). That is, the nanosilicates interrupt the electron transfer and restrict the mobility of the epoxy chains.

Assessment of Low Velocity Impact Damage of Filament Wound Composite Vessels with Surface Protective Materials (필라멘트 와인딩 복합재 압력용기의 저속충격손상 평가에 관한 연구)

  • Lee, Jang-Ho;Kang, Ki-Weon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.8
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    • pp.2741-2749
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    • 2010
  • This paper presents the impact damage behavior of filament wound composite vessels and the effect of surface protective materials on their impact resistance. Using an instrumented impact testing machine, a series of impact tests was performed on the base panels and the protected panels (panels with surface protective materials of rubber, kevlar/epoxy or glass/epoxy laminates) that were cut from the full scale vessel. And the impact damage parameters were used to identify the effect of protective materials on the damage resistance of composite vessels. Damage resistance of the composite vessels was considerably affected by the protective materials regardless of the shape of the indenters. Among the protective materials, glass/epoxy laminates was the most effective mean for improving the damage resistance of composite vessels.

Enhanced Manufacturing and Performance Analysis of Flexible Composite Propeller (유연 복합재료 프로펠러 제작개선 및 성능분석)

  • Lee, Sang-Gab;Nam, Jae-Hyung;Hyun, Beom-Soo;Paik, Bu-Geun;Lee, Chang-Sup;Jang, Hyun-Gil;Nho, In Sik
    • Journal of the Society of Naval Architects of Korea
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    • v.49 no.6
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    • pp.521-527
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    • 2012
  • It is well known that flexible composite material propeller has superior radiation noise characteristics with outstanding damping effects. In this paper, three flexible composite material propellers were produced using compression molding process, and their hydrodynamic performances and radiation noise characteristics were measured. One propeller, C1, was made up from carbon/epoxy composite laminates, and the other two ones, G1 and G2, from glass/epoxy ones. Their fiber arrays were selected by the progressive damage structural analysis of propellers using composite material model MAT_162 (Composite_DMG_MSC) linked with LS-DYNA code. Carbon/epoxy and glass/epoxy composite specimen tests were performed, their damage mechanisms were figured out, and their parameters were calibrated by their progressive damage structural analysis according to their damage criteria.

A Study on the Dielectric Properties and Fabrication method of G F R P Composite Insulating Materials (GFRP 복합절연재료의 제작방법과 유전특성에 관한 연구)

  • Sin, Jung-Hong;Kwak, Young-Soon;Hong, Young-Ki;Park, Jeong-Hoo
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.810-812
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    • 1988
  • This paper is to investigate dielectric properties and new fabrication method of Glass-Cloth/Epoxy composite materials. According to the results of this paper, gelling point temperature is affected significantly on the ambient temperature. And Tan${\delta}$ characteristics of Glass-Colth/Epoxy composite materials is also affected significantly on the state of interior void of glass cloth and interface coupling between epoxy resin and glass cloth.

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Cure simulation for a thick glass/epoxy laminate (유리섬유 강화 후판 복합재료의 경화공정 해석)

  • 오제훈;이대길
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2000.04a
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    • pp.53-58
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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 requires a longer time for full and uniform consolidation. In this work, temperature, degree of cure and consolidation of a 20mm thick unidirectional glass/epoxy laminate were investigated using an experiment and a 3-dimentional numerical analysis considering the exothermic reaction. 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.

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A Study on the Impact Fracture Toughness of Epoxy Matrix Composites (에폭시기지 복합재료의 충격파괴인성에 관한 연구)

  • Kim, Jae-Dong;Jeon, Jin-Tak;Koh, Sung-Wi
    • Journal of Fisheries and Marine Sciences Education
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    • v.9 no.2
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    • pp.188-197
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    • 1997
  • The fracture toughness of three different kinds of epoxy-matrix composites containing the same volume fraction of reinforcement and the variation of fracture toughness of glass-carbon fiber/epoxy hybrid composites due to the change of test temperature and different glass fiber content were investigated in this study. Glass fiber/epoxy composite provided much higher fracture toughness than that of other composites because of the high strain at failure of glass fiber. Particularly the carbon fiber/epoxy composite exhibited the low fracture toughness caused by the low strain energy absorbing capacity of carbon fiber. And it was found that the strain at failure of reinforcement and interfacial delamination absorbing a significant amount of impact energy played an important role to increase fracture toughness of composites. The fracture toughness of the glass-carbon fiber hybrid composites increased with increasing the glass fiber content and decreased with raising the test temperature. The residual stress arising from the different thermal expansion between the matrix and reinforcement influenced the fracture toughness of composites.

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