• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.48-52
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• 2002

This paper describes the need for a ductile Fiber Reinforced Plastic(FRP) reinforcement for Concrete Structures. Using the material hybrid and geometric hybrid, it is demonstrated that the pseudo-ductility Characteristic can be generated in FRP rebar. Ductile hybrid FRP bars were successfully fabricated at Ø3mm and Ø10mm nominal diameters using the braidtrusion process. Tensile and bending specimens from these bars were tested and compared with behavior of stress-strain of steel bar and GFRP rebar

• Journal of Korean Tunnelling and Underground Space Association
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• v.12 no.6
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• pp.451-461
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• 2010

Utilization of the fiber reinforced polymer (FRP) material has been enlarged as a substitution material to the general construction materials having certain long-term problems such as corrosion, etc. However, it could be difficult to apply the FRP material, which has a linear shape generally, to an arch-shaped tunnel structure. Therefore, an attempt has been made in this study to develop a device to form a designed cross section of FRP material by pulling out with a curvature. A sample of the circled FRP product was successfully produced and then the sample has been tested to identify its physical characteristics. Then, intensive feasibility studies on the circled FRP panel to be used for a tunnel lining structure have been carried out by numerical analyses. As a result, it appears that the new circled FRP-concrete composite panel has a high capability to be used for a tunnel lining material without any structural problem.

• Journal of the KSME
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• v.32 no.1
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• pp.18-27
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• 1992

섬유강화 플라스틱을 시초로 복합재료가 상업적으로 생산, 판매되기 시작한지 어언 30여년이 되었다. 뛰어난 기계적 . 화학적 특성을 바탕으로 오늘날 복합재료는 신소재의 한 분야로 굳게 자리잡고 있다. 설계, 성형, 분석기술의 발전과 아울러 유리섬유 복합재료 이후에 특성이 뛰어난 복합재료 소재들이 개발되고 있어 복합재료의 응용범위를 더욱더 넓히고 있다. Boron, carbon, aramid섬유의 개발은 첨단 복합재료의 개발을 가능케 했으며 군용, 우주기기의 개발로 얻어진 결과들은 민간 항공기 또는 스포츠, 레저 분야에 많이 이용되고 있다. 민간 항공기의 많은 부분에 첨단 복합재료로 된 부품들이 사용되고 있으며 복합재료로된 골프채, 낚시대, 테니스채 그리고 스키 등을 우리 주변에서 손쉽게 찾아볼 수 있다. 이 글에서는 고분자 기지 복합재료를 중심으로 그 성형법 및 응용에 대하여 논하고 기타 특수용도 복합재료에 대해서 약술하고자 한다.

• Composites Research
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• v.22 no.4
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• pp.13-19
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• 2009

Adhesive joints are widely used for structural joining applications in various fields and environmental conditions. Polyurethane adhesive is using for LNG carrier with cryogenic temperature condition. Even if similar polyurethane adhesive is used for different substrate, it shows different adhesion properties. Specially, variation of adhesion properties depending on the resin system or fiber is very important factor for selection of adhesive on industrial application. In present study, we got different peel strength according to the different test temperature when different polyurethane adhesive was used for same fiber reinforced composite. The main cause was investigated using by SEM and it was proven that the different adhesion property between glass fiber on composite surface and polyurethane adhesives at cryogenic temperature.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.41 no.2
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• pp.81-85
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• 2017

Fiber-reinforced polymer composites, which are made by combining a continuous fiber that acts as reinforcement and a homogeneous polymeric material that acts as a host, are engineering materials with high strength and stiffness and a lightweight structure. In this study, a shape memory alloy(SMA) reinforced composite actuator is presented. This actuator is used to generate large deformations in single lightweight structures and can be used in applications requiring a high degree of adaptability to various external conditions. The proposed actuator consists of numerous individual laminas of the glass-fiber fabric that are embedded in a polymeric matrix. To characterize its deformation behavior, the composition of the actuator was changed by changing the matrix material and the number of the glass-fiber fabric layers. In addition, current of various magnitudes were applied to each actuator to study the effect of the heating of SMA wires on applying current.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.8
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• pp.849-855
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• 2014

The GFRP composite is used for hot press flow molding of automotive components, and the different flow rates of fiber and plastic are likely to induce fiber orientation and inhomogeneity in the material. However, very limited systematic research studies are available on composite materials with superior flow homogeneity and optimized fiber orientation. The inhomogeneity and fiber orientation issues of GFRP composites have still not been resolved through research. The plain weaving method applied to the GFRP prepreg can improve its recyclability, inhomogeneity, fiber flow, structural stability, fiber deformation, surface smoothness, degree of impregnation, and other mechanical properties. The need for more detailed and thorough studies is evidenced.

• Composites Research
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• v.25 no.4
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• pp.117-125
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• 2012

Warpage of the film insert molded (FIM) part is caused by an asymmetric residual stress distribution. Asymmetric residual stress and temperature distribution is generated by the retarded heat transfer in the perpendicular direction to the attached film surface. Since warpage was not prevented by controlling injection molding conditions, glass fiber (GF) filled composites were employed as substrates for film insert molding to minimize the warpage. Distribution of short GFs was evaluated by using micro-CT equipment. Proper models for micro mechanics, anisotropic thermal expansion coefficients, and closure approximation should be selected in order to calculate fiber orientation tensor and warpage of the FIM part with the composite substrate. After six kinds of micro mechanics models, three models of the thermal expansion coefficient and five models of the closure approximation had been considered, the Mori-Tanaka model, the Rosen and Hashin model, and the third orthotropic closure approximation were selected in this study. The numerically predicted results on fiber orientation tensor and warpage were in good agreement with experimental results and effects of GF reinforcement on warpage of the FIM composite specimen were identified by the numerical results.

• Journal of Adhesion and Interface
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• v.5 no.1
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• pp.21-28
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• 2004

In this work, glass fiber/nylon 6 and woven glass fiber/nylon 6 composites have been fabricated using glass fiber reinforcements sized with 3-chloropropyltrimethoxysilane(CTMS) having a chloropropyl organo-functional group in the molecular chain end. The interfacial shear strength of glass fiber/nylon 6 composite was measured using a single fiber microbonding test and the interlaminar shear strength and the storage modulus of woven glass fabric/nylon 6 composites were measured using a short-warn shear test and a dynamic mechanical analysis, respectively, informing the effect of the concentration of CTMS on the properties. With increasing CTMS concentration, the interfacial properties of the composites were improved. The results on the interfacial shear strength, interlaminar shear strength, interlaminar failure pattern, and storage modulus with varying the CTMS concentration agree with each other.

• Proceedings of the Korean Society For Composite Materials Conference
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• 1999.04a
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• pp.5.2-8
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• 1999

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.6 no.3
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• pp.439-448
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• 1996

The possibility of application or the transparent BK10 glass fiber/PMMA composites as a temperature-or wavelength-sensors was studied. Measurement of diameter and refractive index for glass fibers to be reinforced to PMMA as a function of drawing speed and temperature was done and the appropriate coating methods and solvent for coupling agent was researched. $T_{max%}$ value at which the maximum transmission for the composites occurs could be controlled to be in $31~50^{\circ}C$ by the processing factors such as fiber diameter, fiber vol%, molecular wt. of PMMA. Furthermore, with different wavelength other than 589.3 nm, the $T_{max%}$ value could be controlled to be in $35~55^{\circ}C$. For the sensibility of wavelength for the composites, there was not a wavelength ($\lamda_{max%}$) showing maximum transmission.