• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.586-588
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• 2001

Inner part of FRP specimen was made unidirectionally by pultrusion method and outer part of FRP was made by filament winding method to study the effect of fiber orientatons on the strength of FRP. The strength of bending and compression was simulated and evaluated. The results of simulated strength and evaluated strength were different greately each other. The stress which affect the feature of FRP was simulated to investigate the difference of the results between simulation and evaluation Shear stresses were investigated to the main stress to affect the fracture of FRP.

• 한국해양공학회지
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• 제18권1호
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• pp.63-68
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• 2004

The purpose of this study is to estimate the contribution of concrete and shear reinforcement, in shear carrying capacity, on concrete beams, reinforced with steel and/or FRP rods. The experimental tests for 12 concrete beams, reinforced with steel and/or FRP rods, are carried out. Experimental parameters includes the mechanical properties of reinforcements in shear and bending, and the ratio of shear reinforcement. This study compares the experimental results of shear carrying capacity in concrete beams, reinforced with steel and/or FRP rods, with the proposed equations. According to the experimental results, the effect of the concrete in concrete beams reinforced with FRP rods is decreased with decreasing Young's modulus of longitudinal tensile reinforcement. This results from the large deflection of concrete beams reinforced with decreasing Young's modulus of longitudinal tensile reinforcement. Also, the contribution of shear reinforcement is smaller than the calculated value, using the truss analogy. This results from the fact that the stress redistribution is not exhibited after the break of shear reinforcement.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제49권6호
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• pp.321-327
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• 2000

FRP has been used very much as high strength and electrical insulation materials. The fiber contributes the high strength and modulus to the composite. The main roles of the matrix in composite materials like FRP are to transmit and distribute stresses among the individual fibers. The fiber orientation in FRP has a great effect on the strength of FRP because the strength of FRP mainly depends on the strength of fiber. In this study, compressive and bending stresses of FRP rods were simulated and measured according to the winding orientation of glass fiber. Inner part of FRP was made unidirectionally by pultrusion method and outer part of FRP was made by filament winding method to give fiber orientation to the FRP. The shear stresses had great effect on the strength of FRP although the stress of parallel direction of FRP was much higher. The tendency of compressive and bending strengths with glass fiber orientation was different each other.

• Advances in Computational Design
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• 제7권3호
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• pp.173-188
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• 2022

In modern buildings, glass is considered a structurally unsafe material due to its brittleness and unpredictable failure behavior. The possible use of structural glass elements (i.e., floors, beams and columns) is generally prevented by its poor tensile strength and a frequent occurrence of brittle failures. In this study an innovative modelling based on an equivalent thickness concept of laminated glass beam reinforced with FRP (Fiber Reinforced Polymer) composite material and of glass plates punched is presented. In particular, the novel numerical modelling applied to an embedding Carbon FRP-rod in the interlayer of a laminated structural glass beam is considered in order to increase both its failure strength, together with its post-failure strength and ductility. The proposed equivalent modelling of different specimens enables us to carefully evaluate the effects of this reinforcement. Both the responses of the reinforced beam and un-reinforced one are evaluated, and the corresponding results are compared and discussed. A novel equivalent modelling for reinforced glass beams using FRP composites is presented for FEM analyses in modern material components and proved estimations of the expected performance are provided. Moreover, the new suggested numerical analysis is also applied to laminated glass plates with wide holes at both ends for the technological reasons necessary to connect a glass beam to a structure. Obtained results are compared with an integer specimen. Experimental considerations are reported.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.2
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• pp.1158-1161
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• 2004

This paper presents structural characteristics of station class lightning arresters and electrical characteristics of manufactured ZnO varistor blocks which are usable in those arresters. Three types of station class lightning arresters were investigated and those are a ceramic arrester, a FRP tube type polymer arrester, and a FRP rod type polymer arrester. Each arrester has merits and demerits with structural characteristics. In general, polymer arresters were made of silicon rubber for housing materials, FRP tube or rod for mechanical strength, ZnO blocks for electrical characteristics, and metal parts for electrical contact and the silicon rubber, the housing materials, was directly injected to the arrester module which was assembly composed of electrodes, ZnO blocks and FRP tube or rod, and to prevent the nonlinear electric fields distribution on upper parts of arresters, the grade ring was adopted to the upper electrodes. The reference voltage, nonlinear coefficient, residual voltage, and voltage ratio of manufactured ZnO varistors are 4.90kV, 50, 9.54kV, 1.94, respectively. Compared to designed electrical characteristics, the reference voltage was low for 600v and the voltage ratio was slightly high. However, the characteristics of discharge withstand was so excellent that the mechanical destruction does not occur at the impulse current of $8/20{\mu}s$ 10kA for 100 times.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 C
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• pp.1439-1441
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• 2003

전기절연재의 구조재로 많이 사용되고 있는 FRP(fiber reinforced plastics)는 열경화성 수지를 접착성 결합제(binder)로 하고 고강도 섬유를 보강재로 한 복합재료로서 기계적, 화학적, 전기적 특성이 매우 우수하다. FRP의 기계적 강도는 유리섬유에 의존 하고 있으므로 유리섬유의 방향과 힘을 가하는 방향에 따라서 그 강도의 차이는 매우 크게 나타난다. 본 연구에서는 섬유의 배향에 따른 강도의 변화를 이해하기 위하여 시편을 제작하여 압축강도를 측정하고 압축강도와 응력의 분포를 유한요소법으로 시뮬레이션하였다. FRP rod에 압축응력이 가해졌을 때 섬유의 배향에 따른 파괴강도와 응력의 분포를 유한요소법을 이용하여 시뮬레이션하였고 모델링에는 3-D Shell과 3-D Brick 요소를 사용하였다. 제작된 시편의 강도특성과 시뮬레이션을 통한 응력의 분포를 서로 비교하여 시편의 파괴에 미치는 응력을 고찰하였다.

• 콘크리트학회논문집
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• 제23권3호
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• pp.385-392
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• 2011

이 연구에서는 기존 철근콘크리트 건물의 보-기둥 접합부 및 내진 성능의 개선을 위해 보-기둥 접합부 영역을 기존의 강판 및 FRP보강재(탄소섬유 쉬트, 매입형 탄소섬유봉)를 사용하여 보강한 후 내진 성능을 평가 하였다. 총 6개의 실험체를 제작하고 실험을 수행하여 내진 성능을 평가하였으며, 이 연구의 실험 결과를 근거로 다음과 같은 결론을 얻었다. 기존 철근콘크리트 보-기둥 접합부의 접합부 영역(LBCJ 시리즈)를 보강한 결과 초기 재하시 접합부 영역의 균열 억제 효과와 재하 전 과정을 통하여 보강재의 구속 효과로 인하여 균열 억제 효과가 커서 안정적인 파괴 형태 및 내력 향상 효과를 나타내었다. 기존 철근콘크리트 보-기둥 접합부의 내진 성능을 개선하기 위하여 철근콘크리트 보-기둥 접합부 FRP보강 기술 적용 실험체 LBCJ 시리즈는 표준실험체 LBCJC와 비교하여 최대 내력은 26~50% 증가하였다. 그리고 에너지 소산 능력은 변위 연성 4에서 13.0~14.4% 증가하였다.

• Structural Engineering and Mechanics
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• 제5권4호
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• pp.339-353
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• 1997

Fiber reinforced plastic (FRP) rods provide certain benefits over steel as concrete reinforcement, such as corrosion resistance, magnetic and electrical insulation, light weight, and high strength. FRP composites can be combined with a steel core to form hybrid reinforcing rods that take advantage of properties of both materials. The objective of this study was to characterize the bond behavior of hybrid FRP rods made with braided epoxy-impregnated aramid or poly-vinyl alcohol FRP skins. Eleven rod types were tested using two concrete strengths. Specific topics examined were bond strength, slip, and type of failure in concentric pull-out tests from concrete cubes. From analysis of identical pull-out tests on both hybrid and steel rods, information on relative bond strength and behavior were obtained. It is concluded that strength is similar but slip in hybrid rods is much higher. Hybrid rods failed either by pull-out or splitting the concrete block (with or without yielding of the steel core). Experimental data showed consistency with similar test results presented in the literature.

• 콘크리트학회논문집
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• 제18권6호
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• pp.737-742
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• 2006

1960년대 내부식성이 뛰어난 FRP가 개발되면서 FRP를 이용하여 콘크리트 구조물을 보강하는 방법은 전 세계적으로 광범위하게 사용되었다. 그리고, FRP의 재료적 성능을 최대한 발휘할 수 있는 것으로 FRP에 긴장력을 가하는 방법이 새롭게 대두 되었다. 본 연구에서는 실험 변수를 긴장재의 종류, 긴장력으로 하여 RC보를 표면매립공법으로 보강하여 휨성능 향상에 대한 실험을 실시하였다. 실험 결과 긴장력의 증가에 따라 균열하중 및 항복하중이 표준실험체에 비해 증가하는 것으로 나타났다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1646-1648
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• 2004

수입외자재에 의존하고 있는 GIS(Gas Insu.lated Switchgear)용 FRP 절연로드의 전기적, 기계적 신뢰성시험에 대하여 언급하고자하며, 본 논문에 기술된 신뢰성시험을 통하여 제품특성을 재확인하였으며 최소 GIS의 수명과 동일함을 확인, 파악함으로써 국산화 개발을 실현하였다.