• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.699-702
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• 2004

Plastic shrindage cracking occurs at the exposed surfaces of freshly placed concrete due to consoilidation of the concrete mass and rapid evaporation of water from the surface. This so called shrindage craking is a major concern for concrete, especially for been performed to obtain the plastic shrindage porperties of cellolus fiber reinforced concrete. The results of tests of the cellolus fiber were compared with plain and polypropylene fibers. Test results indicated that cellolus fiber reinforcement showed an aility to reduce the total crack area and maximum crack width significantly.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.374-377
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• 2009

Glass fiber reinforced nylon has been used in many plastic industries. Mechanical properties of reinforced plastics depend upon types of glass fiber as well as loading of glass fiber. Tensile properties of glass fiber reinforced nylon66 have been studied for different glass fiber types and sizes. Types of glass fibers were circular and flat, and diameters were 7, 10, and 13 micrometers. Orientations of glass fibers in the matrix of nylon66 have been analyzed through X-ray CT. Tensile specimens were prepared by cutting out of square plates of $100{\times}100{\times}3mm$ with different angles such as 0, 45, and $90^{\circ}$ to the flow direction. As the loading of glass fiber increases to 45 wt% tensile strength increases up 2.5 times compare with neat nylon66. Anisotropic tensile strength has been observed and minimum tensile strength was measured in the specimen cut from perpendicular to the flow direction.

• Journal of the Korean Wood Science and Technology
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• 제43권5호
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• pp.652-660
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• 2015

To study the bearing characteristics of glass fiber reinforced glulam for structural design, bearing strength tests were performed. Bearing loads were applied in the direction parallel to the grains, and the holes were prepared in such a way that the bolts would bear and support all the layers. The yield bearing strengths of the glass fiber reinforced glulam were found to be similar to those of the non-reinforced glulam, and were almost constant regardless of increases in bolt diameter. The ratio of the experimental yield bearing strength to the estimated bearing strength according to the suggested equation of the Korea Building Code and National Design Specification was 0.91~1.03. For the non-reinforced glulam and the sheet glass fiber reinforced plastic glulam, the maximum bearing load was measured according to the splitting fracture of specimens under bolt. The textile glass fiber reinforced glulam underwent only an embedding failure caused by the bearing load. The failure mode of reinforced glulam according to bearing load will influence the failure behavior of bolted connection, and estimating the shear yield strength of the bolted connection of the reinforced glulam is necessary, not only by using the bearing strength characteristics but also using the fracture toughness of the reinforced glulam.

• 콘크리트학회논문집
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• 제16권3호
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• pp.391-396
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• 2004

소성수축 균열은 경화전 콘크리트의 노출된 표면에서 과도한 수분 증발로 인하여 발생된다. 이러한 소성수축 균열은 특히 도로, 슬래브 및 옹벽 등과 같은 넓은 표면적을 가진 콘크리트 구조물에서 발생하는 가장 큰 문제 중에 하나이다. 본 연구에서는 PVA섬유보강 모르타르 및 콘크리트의 소성수축 특성과 투수성능을 파악하기 위해 실험을 실시하였다. 그 결과 PVA섬유보강 시멘트복합체는 일반 시멘트 복합체 및 폴리프로필렌섬유보강 시멘트 복합체와 비교하여 최대 균열 폭 및 총 균열 면적에 효과적으로 감소하였다. 또한 투수성 실험결과 PVA섬유보강 시멘트 복합체는 폴리프로필렌섬유보강 시멘트 복합체보다 더 낮은 투수성을 나타내었다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 1997년도 추계학술대회 논문집
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• pp.76-81
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• 1997

In the past polyester was usually used as the matrix of all fiber-reinforced plastic (FRP). Nowadays, however, epoxy resin has taken the place of polyester due to its superior properties. If the cutting properties of epoxy resin are unknown, It is difficult to find the optimum cutting conditions of all fiber-reinforced plastic such as CFRP. AFRP. GFRP. In this paper, I will study the cutting properties of epoxy resin by testing surface roughness.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2003년도 추계 학술대회 논문집
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• pp.39-42
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• 2003

최근에 널리 쓰이고 있는 섬유강화 복합재료는 플라스틱 재료가 갖고 있는 가공성의 장점을 충분히 발휘한 재료로서 모재인 수지와 강화재인 강화섬유로 구성되며 사용된 섬유의 종류에 따라 유리섬유강화플라스틱(GFRP : glass fiber reinforced plastic)과 탄소섬유강화플라스틱(CFRP : carbon fiber reinforced plastic)으로 구분된다. 이 두 복합재료가 건설, 선박, 자동차 그리고 우주항공분야에 이르기까지 거의 모든 산업에서 다양하게 이용되고 있다. (중략)

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2008년도 춘계학술대회 논문집
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• pp.201-202
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• 2008

• 한국농공학회논문집
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• 제48권1호
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• pp.61-68
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• 2006

The p-version nonlinear finite element model has been developed to analyze the nonlinear behavior of simply supported RC slabs strengthened with carbon fiber reinforced plastic sheets. The shape function is adopted with integral of Legendre polynomials. The compression model of concrete is based on the Kupfer's yield criterion, hardening rule, and crushing condition. The cracking behavior is modeled by a smeared crack model. In this study, the fixed crack approach is adopted as being geometrically fixed in direction once generated. Each steel layer has a uniaxial behavior resisting only the axial force in the bar direction. Identical behavior is assumed fur tension and compression of steel according to the elastic modulus. The carbon fiber reinforced plastic sheets are considered as reinforced layers of equivalent thickness with uniaxial strength and rigidity properties in the present model. It is shown that the proposed model is able to adequately predicte the displacement and ultimate load of nonlinear simply supported RC slabs by a patch with respect to reinforcement ratio, thickness and angles of CFRP sheets.

• 한국항공운항학회지
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• 제18권4호
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• pp.51-58
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• 2010

Recently, aerospace structures have lightweight trend in order to reduce the cost of fuel and system, Carbon Fiber Reinforced Plastic (CFRP) can give the ability to reduce weight at 20~50% as the substitution of metal alloy, and there are advantages such as high Non-rigid, specific strength and anti-corrosion, but it is difficult to prove its destruction properties due to heterogeneous structure and anisotropy. In this study we designed specimen, inducing distinguishing destructions of material (for example, matrix crack, fiber breakage, and delamination) by using the Carbon Fiber Reinforced Plastic (CFRP) which is used in a real aircraft, to apply acoustic emission technique to aerospace structures. And we gained data via tensile testing and acoustic emission technique, from which each fault signal was classified respectively by using AE parameters and waveform.

• 한국농공학회지
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• 제41권3호
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• pp.59-65
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• 1999

This study has been performed to confirm the three dimensional effect of the crack reduction and the restrained effect of crack growth for the synthetic fiber reinforced soil. Two types of polyrpropylene fiber and low plastic clay(CL) were used for the test. And the test variable were fiber length and so on. The results of the study were summarized as follows ; 1) The mixing of synthetic fiber was effective in reducing crack growth due to adhesion between soil partlcles and synthetic fiber.l Especially initlal crack was delayed, as compared with the pure soil, for about 1 day in case of mono filament synthetic fiber and for about 1 or 2 days in case of fibrillated syntetic fiber. 2) As the content and length of synthetic fiber were increased , the effect of crack reduction was increased. It was found that 0.5% fibrillated synthetic fiber with 40mm length reinforced soil had about 3 times more effective than natural soils. 3) In case of the same fiber content and fiber length, the fibrillated synthetic fiber has nmore effective than the mono filament synthetic fiber for crack reduction.