• Title/Summary/Keyword: Carbon-fiber

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Preparation and Erosion Properties of Reaction-Bonded SiC Reinforced by Carbon Fiber (탄소섬유로 강화된 반응소결 SiC 제조 및 Erosion 특성)

  • 송진웅;임대순;김형욱
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.258-264
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    • 1998
  • Three kinds of reation-bonded SiC that reaction-bonded SiC(RBSC), RBSC reinforced by carbon fiber and RBSC reinforced by activated carbon fiber were prepared for investigating the change of erosion properties. The characteristics of microstructures and the phases have been investigated by using scanning electron microscope and XRD analysis. The hardness test, toughness test and erosion test were camed out. In the cases with no carbon fiber, those kind of specimens had the highest result of hardness test and the lowest result of toughness test. With the increase of carbon fiber content, The hardness and the weight loss were decreased but the toughness was increased in the cases with carbon fiber In the cases with activated carbon fiber those specimens had the highest result of toughness test and the lowest result of hardness test with 30% contents of activated carbon fiber.

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Preparation and Erosion Properties of Reaction-Bonded SiC Reinforced by Carbon Fiber (탄소섬유로 강화된 반응소결 SiC 제조 및 Erosion 특성)

  • 송진웅;임대순;김형욱
    • Tribology and Lubricants
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    • v.15 no.1
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    • pp.59-67
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    • 1999
  • Three kinds of reation-bonded SiC that reaction-bonded SiC(RBSC), RBSC reinforced by carbon fiber and RBSC reinforced by activated carbon fiber were prepared for investigating the change of erosion properties. The characteristics of microstructures and the phases have been investigated by using scanning electron microscope and XRD analysis. The hardness test toughness test and erosion test was carried out. In the cases with no carbon fiber, those kind of specimens had the highest value of hardness and the lowest value of toughness. With the increase of carbon fiber content the hardness and the weight loss were decreased, but the toughness was increased in the cases with carbon fiber. In the cases with activated carbon fiber specimens had the highest value of toughness and the lowest value of hardness with 30% contents of activated carbon fiber.

Characteristics Correlations Between Fiber-Reinforced and Interfacial Adhesion in Carbon fiber reinforced Cement composite Prepared by Slurry Method. (슬러리법에 의한 탄소섬유보강 시멘트복합체의 제조에서 보강섬유와 계면결착제와의 상관특성)

  • Choi, Eung-Kyoo
    • Journal of the Korea Institute of Building Construction
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    • v.2 no.3
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    • pp.131-138
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    • 2002
  • The objective of the study is to examine the characteristic correlations between reinforcing carbon fiber and interfacial adhesion agent since the interfacial adhesion strength between reinforcing carbon fiber and matrices is believed to be an essential element influencing the physical properties in carbon fiber reinforced cement composite using slurry method. The integrity of interfacial adhesion between reinforcing fiber and cement not only affects the quality of fiber reinforced cement composite but also influences to a large degree the physical properties of the cement composite when producing carbon fiber reinforced cement composite using slurry method. Having analyzed the physical properties 1.e., water content, tensile strength, flexural strength and flexural toughness of carbon fiber reinforced cement composite specimens, C-PAM(cation polyacrylamide) was determined to be an optimum interfacial adhesion agent. The study has also demonstrated that interfacial adhesion strength varies largely on the content and type of the reinforcing fiber. Judging from magnified view of the tensile shear cross-section using VMS(video microscope system), interfacial adhesion strength between reinforcing fiber and matrices is affected by the type of interfacial adhesion agent. According to the result of the experiments, C-PAM was determined to be an ideal interfacial adhesion agent when using carbon fiber in producing carbon fiber reinforced cement composite with the optimum content of carbon fiber being established.

Variation of Mechanical Properties by Carbon Fiber Volume Percent of Carbon Fiber Reinforced Reaction Bonded SiC (탄소섬유 강화 반응소결 탄화규소의 탄소섬유 첨가량에 따른 기계적 특성 변화)

  • Yun, Sung-Ho;Yang, Jin-Oh;Cho, Young-Chul;Park, Sang-Whan
    • Journal of the Korean Ceramic Society
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    • v.48 no.5
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    • pp.373-378
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    • 2011
  • The composite added with surface-coated chopped carbon fiber showed the microstructure of a 3 dimensional discretional arrangements. The fiber reinforced reaction bonded silicon carbide composite, containing the 50 vol% carbon fiber, showed the porosity of < 1 vol%, 3-point bending strength value of 250MPa and fracture toughness of 4.5 $MPa{\cdot}m^{1/2}$. As the content of carbon fiber was increased from 0 vol% to 50 vol% in the composite, fracture strength was decreased due to the increase of carbon fiber, which has a less strength than SiC and molten Si. On the other hand, the fracture toughness was increased with increasing the amount of carbon fiber. According to the polished microstructure, carbon fiber was shown to have a random 3 dimensional arrangement. Moreover, the fiber pull-out phenomenon was observed with the fractured surface, which can explain the increased fracture toughness of the composite containing high content of carbon fiber.

A Study on Fatigue Behaviors of RC Beams Strengthened with Carbon Fiber Sheets (CFS로 보강된 RC보의 피로거동에 관한 연구)

  • Park, Jeong-Yong;Cheung, Jin-Hwan;Kim, Seong-Do;Cho, Baik-Soon;Jang, Jun-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.35-38
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    • 2005
  • Carbon fiber sheets are widely used for strengthening the deteriorated RC structures. However most studies on the strengthening method of RC structures with carbon fiber sheets are concerning static problems. The purpose of this experimental study is to present the basic data on fatigue behaviors of. RC beams strengthened with carbon fiber sheets. The experimental parameters of this study are ; 1) the existence of U-shaped carbon fiber sheets at the ends for anchoring, 2) the number of carbon fiber sheet layers in strengthening the RC beams, 3) the load levels of $60\%\~90\%$ of the static bending moment strength, which is obtained form the static tests. Experimental results are estimated from the relationships of load level, displacement, number of repeated load and released energy. It is concluded that U-shaped carbon fiber sheets for end anchoring is very effective and the beams strengthened with one layer of carbon fiber sheet have longer fatigue life than that with three layers.

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Manufacture and Engineering Evaluation of Hybrid Grid Fabrics for Seismic Reinforced Carbon Fiber Composite Yarns. I. Manufacture of Carbon Fiber Composite Yarn and Fabric Design (내진보강용 탄소섬유 복합사 하이브리드 그리드 직물 제조 및 공학적 성능 평가. I. 탄소섬유 복합사 제조 및 최적 직물 설계)

  • Yan, Yu;Cha, Ju Hee;Chai, Charles;Lee, Hyeong Ho;Jeon, Han Yong
    • Textile Science and Engineering
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    • v.55 no.4
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    • pp.280-285
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    • 2018
  • In this study, a carbon fiber composite yarn with the desired stiffness and ductility was fabricated for use in hybrid grid fabrics for seismic reinforcement, and the optimum structures of the grid fabrics were evaluated. Carbon fiber composite yarn was prepared by a double-covering process with carbon fiber/aramid fiber/high-strength PET fiber. It was confirmed that the strength of the carbon fiber composite yarn was greatly increased compared to that of carbon fiber, and the elongation increased by about 0.5%. The TPU (thermoplastic polyurethane) extrusion coating method was more suitable for the carbon fiber composite yarn than urethane impregnation for the coating process. Meanwhile, in the evaluation of yarn fineness and grid structure, thick fibers had greater strengths. When comparing the strength and elongation, the bi-directional grid showed no advantages over the unidirectional grid.

Mechanical properties of carbon fiber sheet and carbon fiber strand sheet based on carbon fibers for the reinforcement of highway bridge RC slabs (도로교 RC 상판 보강을 위한 탄소섬유 기초 carbon fiber sheet와 carbon fiber strand sheet의 역학특성)

  • Won, Chan Ho;Abe, Tadashi;Ahn, Tae-Ho
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.25 no.6
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    • pp.290-293
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    • 2015
  • Recently, a lot of interest has been shown in structural maintenance managements of civil infrastructures. Many researchers have been conducted on various maintenance techniques and repair materials. Among other fiber materials the carbon fiber materials are especially focused on maintenance management of Highway Bridges. Extensive work has been done on Carbon Fiber Sheet (CFS). Nevertheless, Carbon Fiber Strand Sheet (CFSS) is a newly developed material, on which limited work has been done until now. Therefore, in this study bonding the CFSS to RC slab specimen and fatigue resistance evaluation has been conducted. The results demonstrated an increase of 25.3 times more reinforcement of RC slab compared to non-reinforced RC slab. Moreover, compared to CFS-bonded RC slab, The CFSS-bonded RC slab showed 1.2 times greater reinforcement.

Interfacial Properties of Electrodeposited Carbon Fiber/Epoxy Composites using Electro-Micromechanical Techniques and Nondestructive Evaluations

  • Park, Joung-Man;Lee, Sang-Il
    • Macromolecular Research
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    • v.9 no.1
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    • pp.20-29
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    • 2001
  • Interfacial adhesion and nondestructive behavior of electrodeposited (ED) carbon fiber rein-forced composites were evaluated using electro-micromechanical techniques and acoustic emission (AE). The interfacial shear strength (IFSS) of the ED carbon fiber/epoxy composites was higher than that of the untreated fiber. This might be expected because of the possibility of chemical or hydrogen bonding in an electrically adsorbed polymeric interlayer. The logarithmic electrical resistivity of the untreated single-carbon fiber composite increased suddenly to infinity when fiber fracture occurred, whereas that of the ED composite increased relatively gradually to infinity. This behavior may arise from the retarded fracture time due to enhanced IFSS. In single- and ten-carbon fiber composites, the number of AE signals coming from interlayer failure of the ED carbon fiber composite was much larger than that of the untreated composite. As the number of the each first fiber fractures increased in the ten-carbon fiber composite, the electrical resistivity increased stepwise, and the slope of the logarithmic electrical resistance increased.

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Accelerated Aging Characteristics of Electroconductive Paper (탄소섬유를 첨가한 전도성 종이의 강제열화 특성)

  • Kim, Bong-Yong
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.2
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    • pp.24-30
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    • 2011
  • The accelerated aging characteristics of electroconductive papers manufactured with a mixture of carbon fiber were investigated by heating in dry oven. By accelerated aging time, the tensile strength, tensile stretch of the papers were decreased more slowly with increase of carbon fiber content, but the electrical conductivity was more rapidly decreased in case of high carbon fiber content. The weight loss of papers by thermal analysis were reduced as increasing the carbon fiber content. These results were indicated that the electrical conductivity of carbon fiber was diminished easily by heat aging, but thermal characteristic of carbon fiber was much better than that of wood pulp.

Optimum mixture of high performance hybrid fiber reinforced concrete using fractional experimental design by orthogonal array (일부실시 직교배열 실험설계에 의한 고성능 하이브리드 섬유보강 콘크리트 배합 최적화)

  • Park, Tae-Hyo;Noh, Myung-Hyun;Park, Choon-Keun
    • Proceedings of the Korea Concrete Institute Conference
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    • pp.341-344
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    • 2004
  • In the present research, slump, modulus of rupture (MOR) and flexural toughness $(I_{30})$ of high performance hybrid fiber reinforced concrete (HPHFRC) mixed with micro-fiber (carbon fiber) and macro-fiber (steel fiber) and replaced with silica fume were assessed with the analysis of variance (ANOVA). Steel fiber was a considerable significant factor in aspect of the response values of MOR and boo Based on the significance of factors related to response values from ANOVA, following assessments were available; Slump decrease: carbon fiber >> steel fiber > silica fume; MOR: steel fiber > silica fume > carbon fiber; $I_{30}$: steel fiber > carbon fiber > silica fume. Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $5.0\%$, and Steel fiber $1.0\%$, carbon fiber $0.25\%$ and silica fume $2.5\%$ were obtained as the most optimum mixture.

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