• Title/Summary/Keyword: aramid fiber

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Interfacial Adhesion Properties of Plasma Treated Aramid Fiber with Chloroprene Rubber (아라미드 섬유의 플라즈마 처리에 따른 클로로프렌 고무와의 계면접착 특성)

  • Lee, Tae-Sang;Kim, Book-Sung;Choi, Han-Na;Lee, Kee-Yoon;Lee, Seung-Goo
    • Textile Science and Engineering
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    • v.47 no.3
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    • pp.205-211
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    • 2010
  • The interfacial adhesion between the chloroprene rubber (CR) and aramid fiber treated with cold plasma was investigated. The surface properties of aramid fiber and CR were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and dynamic contact angle (DCA) measurements. The surface morphology of the aramid fiber changed with the plasma treatment time, power and gas flow rate. The interfacial shear strength, between the plasma treated aramid fiber and CR, was calculated using the pull-out test results. The interfacial adhesion properties of the aramid fabric/CR composite were determined using a T-peel test. Consequently, the strong interaction between the plasma treated aramid fiber and CR matrix improved the interfacial adhesion strength of the composite.

Torsional behaviour of reinforced concrete beams retrofitted with aramid fiber

  • Kandekar, Sachin B.;Talikoti, Rajashekhar S.
    • Advances in concrete construction
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    • v.9 no.1
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    • pp.1-7
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    • 2020
  • Retrofitting is an alteration of existing member or component of the structure. In civil engineering point of view, it is called strengthening of the old structure. Deterioration of structures may be due to aging, corrosion, failure of joints, earthquake forces, increase in service loads, etc. Such structures need urgent repair, retrofitting and strengthening to avoid collapse, cracking and loss in strength or deflection. Advanced techniques are required to be developed for the repair of structural components to replace conventional techniques. This paper focuses exclusively on torsional behaviour of Reinforced Concrete (RC) beams and retrofitted RC beams wrapped with aramid fiber. Beams were retrofitted with aramid fiber by full wrapping and in the form of 150 mm wide strips at a spacing of 100 mm, 150 mm, 200 mm respectively using epoxy resin and hardener. A total 15 numbers of RC beams of 150 mm×300 mm×1300 mm in size were cast, 3 beams are tested as control specimens, and 12 beams are tested for torsion up to the failure and then retrofitted with aramid fiber. Experimental results are validated with the help of data obtained by finite element analysis using ANSYS. The full wrapping configuration of aramid fiber regains 105% strength after retrofitting. With the increase in spacing of fabric material, torsional strength reduces to 82% with about 45% saving in material.

Strengthening Effects of Slabs by Aramid Fiber Sheet (아라미드섬유 쉬트에 의한 슬래브의 보강효과)

  • Yeon, Kyu-Seok;Kang, Young-Sug;Kim, Hyung-Woo;Lee, Youn-Su;Kim, Nam-Gil
    • Magazine of the Korea Concrete Institute
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    • v.11 no.2
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    • pp.105-113
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    • 1999
  • This study was conducted to evaluate the structural behaviors of Aramid fiber sheet reinforced slabs. Seven concrete slabs with $45{\times}8.5{\times}200cm$ were made for this experiment one slab with out being reinforced completely loaded until failure and the maximum load was obtained from this test. 70% of the maximum load was applied to 3 Aramid fiber sheet reinforced slabs after cracking and to the rest of 3 Aramid fiber sheet reinforced slabs without loading and cracking. Test results shows that maximum loading flexural rigidity and ductility for the Araimid fiber sheet reinforced slabs after initial cracking are similar as those for the Armied fiber sheet reinforced slabs without loading and cracking.

Estimation of Fatigue Characteristics Using Weibull Statistical Analysis with Aramid Fiber on LNGC Secondary Barrier (LNGC 2차 방벽에 적용된 Aramid 섬유의 Weibull 통계 분석을 이용한 피로특성 평가)

  • Park, Jin Hyeong;Oh, Dong Jin;Kim, Min Gyu;Kim, Myung Hyun
    • Journal of the Society of Naval Architects of Korea
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    • v.54 no.5
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    • pp.415-420
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    • 2017
  • Insulation systems in Liquefied Natural Gas Carriers (LNGC) are vulnerable to sloshing impact and fatigue loads because of waves. If gas leaks into the primary barrier, the Flexible Secondary Barrier (FSB) prevents the leakage of gas in this system. Fatigue strength of the FSB largely depends on the behavior of composite materials. In this study, a new system is applied to the FSB using aramid fiber to improve the fatigue strength of the secondary barrier, with the intention of replacing conventional E-glass fibers. The manufacturing method involved varying the ratio of the aramid fiber to the E-glass fiber for optimum design of the FSB. The fatigue tests results of the secondary barrier using aramid fiber were superior to that using E-glass fiber. The statistical analysis is performed to obtain the fatigue test results and estimate the probability of failure as well as the design guideline of LNGC secondary barriers.

The FSI Analysis Evaluation of Strength for the Wind Turbine Rotor Blade Improved by the Aramid Fiber (아라미드섬유 보강 풍력발전기 로터 블레이드의 연성해석 강도평가)

  • Kim, Seok-Su;Kang, Ji-Woong;Kwon, Oh-Heon
    • Journal of Power System Engineering
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    • v.19 no.4
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    • pp.17-23
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    • 2015
  • Because of the energy resources shortage and global pollution, the wind power systems have been developed consistently. Among the components of the wind power system, the rotor blades are the most important component. Generally it is made of GFRP material. Recently, GFRP material has been replaced by CFRP composite material in the blade which has an aerodynamic profile and twisted tip. However the failures has occurred in the trailing edge of the blade by the severe wind loading. Thus, tougher material than CFRP material is needed as like the aramid fiber. In this study, we investigated the mechanical behaviors of the blade using aramid fiber composites about wind speed variation. One-way FSI (fluid-structure interaction)analysis for the wind rotor blade was conducted. The structural analyses using the surface pressure loading resulted from wind flow field analysis were carried out. The results and analysis procedure in this paper can be utilized for the best strength design of the blade with aramid fiber composites.

Dyeing Properties of Easily Dyeable m-Aramid Knit Fabric (염색이 용이한 메타 아라미드 편성물의 염색성에 관한 연구)

  • Lee, Bum Hoon
    • Textile Coloration and Finishing
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    • v.32 no.3
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    • pp.128-134
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    • 2020
  • Heat and flame protecting cloth is usually made of meta aramid fiber because of its own properties. But the high inter molecular hydrogen bonding and high Tg is the reason of the difficulty to dye meta aramid fiber. Recently, it was commercialized that the easily dyeable meta aramid fiber(AMD) for improving dyeability. In this study, the dyeing properties of AMD dyed with cationic dyes were investigated. The K/S values of AMD were 5~10% higher than these of general meta aramid fiber(AM) in the case of 1%owf caused by the lower crystallinity of AMD. The difference between K/S values of AMD and AM was increased as increasing dyeing concentration. The washing and rubbing fastness grade of AM and AMD were similar and good to very good.

Flexural Behavior of Reinforced Concrete Beams Strengthened with Aramid Fiber-Reinforced Sheet (Aramid섬유시트를 사용한 철근콘크리트보의 보수.보강)

  • 김진수;박재만
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.840-845
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    • 1999
  • In this study, it was experimentally investigated the effectiveness of repair and strengthening methods for RC beams deteriorated under severs enviromental conditions. Polymer cement were employed to restore the sectional loss and aramid fiber-reinforced sheet was used to reinforce the surface subject to tension. Repaired and strengthened reinforced-concrete samples were subjected to loading tests. The tests revealed that the sectional restoration enhanced the loading capability of the sample structures. Additional strengthening with one aramid fiber-reinforced sheet improved 18% of yielding load and 30% of ultimate load of the structure. Reinforcing with two aramid fiber-reinforced sheets brought about an enhancement of 22% of yielding loading and 49% of ultimate load.

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A Study on the Fatigue Behavior of ARALL and Manufacturing of ARALL Materials (ARALL재의 개발과 이의 파괴거동에 관한 연구)

  • 손세원;이두성;장정원;홍성희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.908-912
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    • 1996
  • FRMLs consist of thin sheets of high strength metal, which are laminated using a structural adhesive and high strength fibers. ARALL(Aramid-fiber Reinforced Aluminum alloy Laminates) of FRMLs is a new class of hybrid material. HERALL(Heracron Reinforced Aluminum Laminate) i.e. domestic ARALL is made of homemade aramid fibers, adhesives and adhesive technique. Domestic aramid fiber is Heracron manufactured by KOLON and domestic adhesive is epoxy resin manufactured by Han Kuk Fiber. In this study, Fatigue crack propagation behavior was examined in a 2024-T3 aluminum alloy/aramid-fiber epoxy 3/2 laminated composites, HERALL and ARAL $L^{ⓡ}$-2 LAMINATE comparing with 2024-T3 aluminum alloy. The extrinsic toughening mechanisms in HERALL and ARALL were examined, the crack bridging behavior of fibers was analyzed by new algorithm, which measures crack bridging stress, and the crack bridging zone length was measured.

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Surface Modification Effect and Mechanical Property of para-aramid Fiber by Low-temperature Plasma Treatment (저온 플라즈마 처리를 이용한 파라 아라미드 섬유의 표면 개질 효과 및 역학적 특성(2))

  • Park, Sung-Min;Son, Hyun-Sik;Sim, Ji-Hyun;Kim, Joo-Young;Kim, Taekyeong;Bae, Jin-Seok
    • Textile Coloration and Finishing
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    • v.27 no.1
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    • pp.18-26
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    • 2015
  • para-aramid fibers were treated by atmosphere air plasma to improve the interfacial adhesion. The wettability of plasma-treated aramid fiber was observed by means of dynamic contact angle surface free energy measurement. Surface roughness were investigated with the help of scanning electron microscopy and atomic force microscopy. The tensile test of aramid fiber roving was carried out to determine the effect of plasma surface treatments on the mechanical properties of the fibers. A pull-out force test was carried out to observe the interfacial adhesion effect with matrix material. It was found that surface modification and a chemical component ratio of the aramid fibers improved wettability and adhesion characterization. After oxygen plasma, it was indicated that modified the surface roughness of aramid fiber increased mechanical interlocking between the fiber surface and vinylester resin. Consequently the oxygen plasma treatment is able to improve fiber-matrix adhesion through excited functional group and etching effect on fiber surface.

Study of Dyeing Properties by Swelling Agent on meta-aramid Fiber with Cationic Dyes (Swelling agent에 따른 메타계 아라미드 섬유의 Cationic dye 염색특성)

  • Kim, Eun-Mi;Park, Chung-Won;Choi, Jae-Hong
    • Textile Coloration and Finishing
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    • v.24 no.1
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    • pp.1-7
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    • 2012
  • Dyeing and fastness characteristics of 100% meta-aramid fiber were investigated with cationic dyes and swelling agents under various dyeing conditions such as dyeing temperature and pH of dye bath. Dye exhaustion started at around $80^{\circ}C$ and settled down at $130^{\circ}C$. Among swelling agents used, N-methyl formanilide showed comparatively higher K/S values comparing to 1-phenoxypropan-2-ol. Under weak acidic conditions in the range pH 5 to 7, the exhaustion of cationic dyes could be enhanced leading to higher adsorption and stability of colorimetric property. Wash and rubbing fastness were generally good but low light fastness found can be attributable to the poor photo-stability of the cationic dyes.