• Title/Summary/Keyword: aramid

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Experimental Study on Interfacial Bond Stress between Aramid FRP Strips and Steel Plates (아라미드 FRP 스트립과 강판 사이의 계면 부착응력에 관한 실험적 연구)

  • Park, Jai Woo;Ryoo, Jae Yong;Choi, Sung Mo
    • Journal of Korean Society of Steel Construction
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    • v.27 no.4
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    • pp.359-370
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    • 2015
  • This paper presents the experimental results for the interfacial bond behaviour between AFRP strip and steel members. The objective of this paper is to examine the interfacial behavior and to evaluate the interfacial bond stress between Aramid FRP strips and steel plates. The test variables were bond length and AFRP thickness. 18 specimens were fabricated and one-face shear type bond tests were conducted in this study. There were two types of failure mode which were debonding and delamination between AFRP strip and steel plates. From the test, the load was increased with the increasing of bond length and AFRP thickness, which was observed that maximum increase of 63 and 86% were also achieved in load with the increasing of bond length and AFRP thickness, respectively. Finally, bond and slip characteristics had the elastic bond-slip model and it was observed that bond strength and fracture energy were not affected by bond length and AFRP thickness.

Heat Treatment Effects on the Thermal Stability and Mechanical Property of Spider Silks from Nephila clavata and Bassaniana decorata (무당거미와 나무껍질게거미줄의 열 안정성 및 기계적 성질에 관한 열처리 효과)

  • Chang, So-Yeon;Lee, Ji-Hye;Lee, Ju-Ha
    • Korean journal of applied entomology
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    • v.48 no.1
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    • pp.109-115
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    • 2009
  • The thermal stability and mechanical properties of Nephila clavata and Bassaniana decorata spider silks were measured and compared with those of aramid and polyester fibers. The thermal stability of the spider silk was lower than those of the commercial aramid and polyester fibers. However, the mechanical properties of the spider silk were far superior to that of the polyester fiber. The effect of the water content of the spider silk on its thermal stability and mechanical property was examined by conducting the silk to heat treatment at $100^{\circ}C$ under vacuum for various times. The results indicated that spider silk subjected to heat treatment for 1.5 hr had excellent thermal stability and mechanical property.

Performance Evaluation of Protective Clothing Materials for Welding in a Hazardous Shipbuilding Industry Work Environment (조선업의 유해 작업환경 대응을 위한 용접 보호복 소재의 성능평가 연구)

  • Kim, Min Young;Bae, Hyun Sook
    • Fashion & Textile Research Journal
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    • v.15 no.3
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    • pp.452-460
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    • 2013
  • This study conducted a performance evaluation of protective clothing materials used for welding in a hazardous shipbuilding industry work environment. The welding process was selected as the one that most requires industrial protective clothing according to work environment characteristics. Flame proofing and convection heat protection performance (HTI) in the heat transfer characteristics of protective clothing material were indicated in the order of SW1(Oxidant carbon)>SW2(silica coated Oxidant carbon)>SW4(Oxidant carbon/p-aramid)>SW3(flame proofing cotton). However, radiant heat protection performance (RHTI) and the heat transfer factor (TF) were indicated in the order of SW1>SW4>SW2>SW3 and showed different patterns from the convection heat protection performance. SW1 showed superior air permeability and water vapor permeability. The tensile strength and tear strength of welding protective clothing material were indicated in the order of SW4>SW2>SW3>SW1 and showed that a blend fabric of p-aramid was the most superior for the mechanical properties of SW4. SW1 had excellent heat transfer properties in yet met the minimum performance requirements of tensile strength proved to be inappropriate as being a material for welding protective clothing. The abrasion resistance of woven fabric proved superior compared to nonwoven fabric; however, seam strength and dimensional change both met the minimum performance requirements and indicated that all samples appeared non-hazardous. Finally, oxidant carbon/p-aramid blend fabric appeared appropriate as a protective clothing materials for welding.

Development of Reinforcement Grout Materials Using Reinforcing Fiber and Blast Furnace Slag Powder (보강섬유와 고로슬래그 미분말 함유량에 따른 차수그라우트재 개발)

  • Seo, Hyeok;Kim, Daehyeon
    • Journal of the Korean Geosynthetics Society
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    • v.18 no.3
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    • pp.101-112
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    • 2019
  • The grouting method is utilized to reinforce and waterproof poor grounds, enhance the bearing capacity of geo-structures damaged from differential settlement. The purpose of this research is to improve the compressive strength and degree of grout using reinforcing fibers and blast furnace slag powder. In this regard, this study has conducted uniaxial compression tests for the specimens with high ratios (higher than 50%) of blast furnace slag powder. The carbon fiber content was increased by 0, 0.5, and 1.0% to coMpare its compressive strength with that of aramid fiber. The uniaxial compressive strength increased with the increase of fiber content and the bridging activity by fiber in cement tended to increase uniaxial compressive strength. Based on the results, it was confirmed that the aramid fiber has a gel time of 14 seconds and the uniaxial compressive strength is more than 3 Mpa coMpared to carbon fiber.

The Roles of Reinforcing Fibers on the Performance of Automotive Brake Pads (자동차용 마찰재의 성능에 미치는 강화섬유의 역할)

  • Lim, Hyun-Woo;Yoon, Ho-Gyu;Jang, Ho
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2000.06a
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    • pp.173-179
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    • 2000
  • The friction and wear characteristics of brake friction materials reinforced with aramid fiber, carbon fiber, glass fiber, and potassium titanate whiskers were investigated using a pad-on-disk type friction tester. In particular, the morphology of rubbing surfaces was carefully investigated to correlate the friction performance and properties of transfer films. The aramid fiber reinforced specimen showed severe oscillation of friction coefficient at low speed and low applied pressure. The carbon fiber reinforced specimen showing better friction stability exhibited uniform and stable transfer film than any other specimens. The glass fiber reinforced specimen showed unstable friction changes at high speed and high-applied pressure and the non-uniform transfer film was observed in both friction material and rotor surface. The potassium titanate whiskers reinforced specimen showed stable coherent transfer film. The wear test exhibited the potassium titanate whiskers reinforced specimen was lowest in wear amount and glass fiber reinforced specimen showed the severe wear.

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The Effect of Resin Mixture Ratio on Characteristics of Tensile and T-peel Strength in Al/AFRP Laminates (Al/APRP 적층재의 수지혼합비가 인장 및 티-필(T-peel) 강도 특성에 미치는 영향)

  • Song, Sam-Hong;Kim, Cheol-Woong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.11
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    • pp.2374-2382
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    • 2002
  • Aluminum alloy/aramid fiber reinforced plastic(Al/AFRP) laminates consists of high strength metal(A15052) and laminated aramid fiber with structural adhesive bond. The mixture ratio effect of epoxy resin curing agent accelerator on the tensile strength and T-peel strength characteristic in Al AFRP laminates were investigated in this study. The epoxy. diglycidylether of bisphenol A(DCEBA), It'as cured by methylene dianiline(MDA) with or without an accelerator(K-54). Eight different kinds of resin mixture ratios were selected for the test , five kinds of Al/AFRP laminates were named as Al/AFRP(1) and three others of Al/AFRP laminates were named as Al/AFRP(2). The comparison of tensile strength and T-peel strength with variation of resin mixture ratio were studied. Respectively. Al/AFRP(1) and Al/AFRP(2) indicated approximately 6.0 times and 7.0 times more improved maximum tensile strength in comparison with those of monolithic A15052. Al/AFRP(2) indicated approximately 1.5 times more impoved maximum T-peel strengths in comparison with those of Al/AFRP(1). As results. Al/AFRP(2) turned out to have more effective characteristics on the tensile strength and T-peel strength than those of Al/AFRP(1).

Physiological Responses of Wearing Protective Welding Clothing Considering the Work Environment of the Shipbuilding Industry (조선업 작업환경을 고려한 용접 보호복 착의시 인체생리반응)

  • Kim, Min-Young;Bae, Hyun-Sook
    • Journal of the Korean Society of Clothing and Textiles
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    • v.37 no.2
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    • pp.235-245
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    • 2013
  • Physiological responses and subjective sensations were evaluated for wearing protective welding clothing in consideration of the work environment for the shipbuilding industry. Experimental clothing was made of oxidant carbon nonwoven fabric (SW2) and oxidant carbon/p-aramid blended fabric (SW4). The values of all items in physiological responses were higher upon wearing oxidant carbon experimental clothing versus wearing oxidant carbon/p-aramid experimental clothing (p<.001). The results of the wearing evaluation in the welding work on-site showed that existing leather protective clothing had a very low satisfaction of permeability, weight sensation and wearing sensation. For the wearing sensation of experimental clothing with SW2, permeability and durability were poor and the pressure and weight sensation satisfaction was very high. In case of SW4, the satisfaction was very high in functional movement, pressure, weight sensation and management aspects; subsequently, the overall wearing satisfaction was very good.