• 제목/요약/키워드: Glass fiber reinforced Plastic

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Breakdown, V-t and Degradation Characteristics of Insulation in Liquid Nitrogen for HTS Transformer (고온초전도 변압기를 위한 액체질소 중 절연 파괴, V-t. 열화 특성)

  • Nguyen, Van-Dung;Joung, Jong-Man;Baek, Seung-Myeong;Lee, Chang-Hwa;Suck, Song-Hee;Kim, Sang-Hyun
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.53 no.6
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    • pp.316-323
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    • 2004
  • HTS transformer is one of the most promising devices to supply enough electric energy for quick increase consumption. However, for practical design of the HTS transformer, it is necessary to establish the research on breakdown, V-t characteristics, degradation, and so on. In this paper, we discussed breakdown characteristics and V-t characteristics of polyimide/L$N_2$ and glass fiber reinforced plastic/$LN_2$ composite insulations. These composite insulations have been used as turn-to-turn and layer-to-layer insulations for HTS transformer respectively, Moreover, we investigated the degradation of these insulation samples after breakdown using microscope and SEM photograph.

Characterization of elastic properties of pultruded profiles using model updating procedure with vibration test data

  • Cunha, Jesiel;Foltete, Emmanuel;Bouhaddi, Noureddine
    • Structural Engineering and Mechanics
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    • v.30 no.4
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    • pp.481-500
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    • 2008
  • In this paper, a model updating technique in dynamics is used to identify elastic properties for pultruded GFRP-Glass Fiber Reinforced Plastic framed structural systems used in civil construction. Traditional identification techniques for composite materials may be expensive, while this alternative approach allows to identify several properties simultaneously, with very good precision. Furthermore, the procedure of a non-destructive type has a relatively simple implementation. Properties describing the mechanical behavior for beam and shell finite element modeling are identified. The used formulation is based on the minimization of eigensolution residuals. Important points concerning model updating procedures have been observed, such as the particular vibrational behavior of the test structure, the modeling strategies and the optimal placement of the sensors in the experimental procedure. Results obtained by experimental tests show the efficiency of the proposed procedure.

A Study on Life Characteristics of Insulator for Stability of a HTS equipment (고온초전도 기기의 신뢰성 확보를 위한 고려한 절연재료의 수명 특성 연구)

  • Baek, Seung-Myeong;Kim, Hyun-Hee;Kim, Sang-Hyun
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.965-966
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    • 2007
  • For practical electrical insulation design of high temperature superconducting (HTS) power apparatuses, knowledge of the dielectric behavior of insulators in cryogenic liquid such as liquid nitrogen ($LN_2$) is essential. So in this paper, we discussed experimental investigations of breakdown and V-t characteristics of several insulators such as Kapton and glass fiber reinforced plastic (GFRP) that are candidates of insulator for HTS apparatus in cryogenic liquid. And we investigated the degradation of these insulation samples after breakdown with the microscope and SEM photograph. Moreover, survival and hazard analysis was performed.

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A Study on the Application of RFID Technique for Improving Small Vessel Safety Management System (소형선박 안전관리 개선을 위한 무선인식 (RFID)기술적용 시스템 구축방안 연구)

  • Jeong, Yong-Geun;Choi, Kyong-Il;Lee, Hee-Joon
    • Journal of Korea Ship Safrty Technology Authority
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    • s.28
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    • pp.19-35
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    • 2010
  • 본 연구에서는 2톤 미만 소형선박에 대한 효율적인 안전관리를 위하여 RFID(Radio Frequency IDentification)시스템의 실제 해양환경에서의 도입타당성을 검증하였다. 이를 위하여 FRP Fiber Glass Reinforced Plastic 선박을 중심으로 목선과 알루미늄선에 태그를 부착하고 이동형 Reader를 활용하여 태그정보를 확인하는 실제 해양환경 인식실험을 실시하였다. 해양환경 인식실험을 위하여 4종의 태그를 선정하였으며 다양한 각도에서 인식률 및 인식거리를 측정하여 그 특성을 파악하고자 하였다. 특히, 선박에 설치된 무선설비로 인한 전파장애, 염분, 수분, 온도 등 열악한 해양환경에서 무선인식(RFID)기술의 기술적 환경적 문제점 유무를 분석하였으며, 2톤 미만 소형선박 소유자의 편의성 제고를 위하여 유관기관과의 관련정보 공유를 통한 연계방안으로 무선인식(RFID)기술을 적용한 효율적인 선박안전관리체계 구축방안을 강구하여 선박등록 및 검사업무에서의 활용방안을 제시하였다.

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A Study on the Standard of Ship Hull Construction for Aluminium Alloys Fishing Boats (알루미늄 합금제 어선건조를 위한 선체구조기준 설정에 관한 연구)

  • Hong, Bong-Ki
    • Journal of Fisheries and Marine Sciences Education
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    • v.12 no.1
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    • pp.22-82
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    • 2000
  • The ship hull construction materials of fishing boat has changed in order that wooden, steel, and fiber glass reinforced plastic(FRP). The fishing boat made from FRP has increased every year because that materials has proved excellent of the characteries for fishing boats construction members. Recently, FRP tend towards evasion for the pollution of air enviroment. Therefore. the materials of fishing boat construction must be exchanged by another one. Aluminium alloys must be recommended for fishing boats construction mateials because that is light weight and corrosion resisting in the sea water. Regulation of the standard of ship hull construction for aluminium alloys fishing boats did not enact laws in the interior now. Therefore, this regulation was studied by the following items. that is Rudder, Bottom construction, Side hull plate construction, Deck plate construction, piller. Water tight bulkhead, Deep tank, Fish tank, Stern construction, Superstructure, Deck house construction, Hatch, Engine room opening, Hatch opening, Bulwark, Welding and Rivet etc. A study on the regulation will be contributed to enact laws for fishing boat construction of aluminium alloys.

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Breakdown Characteristics of Insulation Materials for a Termination of Power Transmission Class HTS Cable

  • Kwag Dong-Soon;Cheon Hyeon-Gweon;Choi Jae-Hyeong;Kim Sang-Hyun
    • Progress in Superconductivity and Cryogenics
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    • v.8 no.2
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    • pp.37-42
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    • 2006
  • A research on several characteristics such as volume breakdown and surface discharge of insulators for a termination of power transmission class HTS cable was performed. We investigated the surface discharge of glass fiber reinforced plastic (GFRP) under air, cryogenic nitrogen gas and nitrogen gas media. The breakdown characteristics of these media were studied. Experimental results revealed that flashover voltage greatly depends on pressure, temperature, the kinds of insulating media and voltages, but it is slightly affected by shape and material of electrode. The breakdown voltage of liquid nitrogen, cryogenic nitrogen gas and nitrogen gas deeply depends on the shape and dimension of electrode, kinds of voltages and pressure. Moreover, the breakdown voltage of cryogenic nitrogen gas and flashover voltage of GFRP in the cryogenic nitrogen gas is also influenced by temperature and vapour-mist density of the gas.

Development of Glass Fiber Composite Material to Extend the Life of Fly Ash Transport Pipe: Wear Test (비회 운송관의 수명연장을 위한 유리섬유 복합재의 개발: 내마모성 평가)

  • Jeong, Gyu-Sang;Chang, Yoon-Sang
    • Clean Technology
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    • v.15 no.1
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    • pp.16-22
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    • 2009
  • In this study, a fiber reinforced plastic (FRP) pipe with superior wear resistance was developed to replace the fly ash pipe of cast iron. Wear test was performed with various combinations of SiC filler and resin materials of unsaturated polyester, vinylester, epoxy, and phenol. Test results of ASTM D4060 showed the optimal combinations of resin, filler size, and resin/filler ratios. Test results of comparison between FRP and cast iron showed the possibility to replace cast iron pipe with the FRP pipe. Field test executed to compare the wear resistance between cast iron pipe and developed FRP pipe showed the superiority of the FRP pipe.

Evaluation of Failure Mode in Concrete Beam Restrengthened with GFRP with Various Initial Conditions (GFRP로 보강된 다양한 초기 조건의 콘크리트보의 파괴 거동 평가)

  • Jin-Won Nam;Seung-Jun Kwon
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.11 no.3
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    • pp.177-183
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    • 2023
  • Various failure modes occur in the concrete beams reinforced with GFRP(Glass Fiber Reinforced Plastic) under initial condition and repairing patterns. In this study, the failure behaviors of concrete beams restrengthened with GFRP sheet with slightly higher elastic modulus than concrete were investigated. For the tests, concrete beams with 24 MPa were manufactured, and the effects of initial notch, overlapping, end-strip reinforcement, and fiber anchors were analyzed on failure load. The cases of GFRP overlap around notch and the initial notch showed increasing failure loads similar to those of normal restrengthened case since the epoxy of the saturated GFRP sufficiently repaired the notch area. Compared to the control case without restrengthening of GFRP, the concrete with initial notch showed 0.78 of loading ratio and normal restrengthening showed 4.43~5.61 times of increasing ratio of failure loading, where interface-debonding from flexural crack were mainly observed. The most ideal failure behavior, break of GFRP, was observed when end-strip over 1/3 height from bottom and fiber anchor were installed, which showed increasing failure load over 150 % to normal restrengthening.

Acoustic Emission Characteristics and Fracture Behaviors of GFRP-Aluminum Honeycomb Hybrid Laminates under Compressive and Bending Loads (GFRP-알루미늄 하니컴 하이브리드 적층판의 압축 및 굽힘 파괴거동과 음향방출해석)

  • Lee, Ki-Ho;Gu, Ja-Uk;Choi, Nak-Sam
    • Composites Research
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    • v.22 no.6
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    • pp.23-31
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    • 2009
  • This paper investigated acoustic emission (AE) characteristics in association with various fracture processes of glass fiber reinforced plastic skin/ aluminum honeycomb core (GF-AH) hybrid composites under compressive and bending loads. Various failure modes such as skin layer fracture, skin/core interfacial fracture, and local plastic yield buckling and cell wall adhesive fracture occurring in the honeycomb cell wall were classified through the fracture identification in association with the AE frequency and amplitude analysis. The distribution of the event-rate in which it has a high amplitude showed a procedure of cell wall adhesive fracture, skin/core interfacial debonding and fiber breakage, whereas distribution of different peak frequencies indicated the plastic deformation of aluminum cell wall and the friction between honeycomb walls. Consequently, the fracture behaviors of GF-AH hybrid composites could be characterized through a nondestructive evaluation employing the AE technique.

Comparison of the Stress Concentration Factors for GFRP Plate having Centered Circular Hole by Three Resource-Conserving Methods

  • Gao, Zhongchen;Park, Soo-Jeong;Kim, Yun-Hae
    • Composites Research
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    • v.29 no.6
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    • pp.388-394
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    • 2016
  • Fiber reinforced plastic (FRP) composites have drawn increasing attentions worldwide for decades due to its outstanding properties. Stress concentration factor (SCF) as an essential parameter in materials science are critically considered in structure design and application, strength assessment and failure prediction. However, investigation of stress concentration in FRP composites has been rarely reported so far. In this study, three resource-conserving analyses (Isotropic analysis, Orthotropic analysis and Finite element analysis) were introduced to plot the $K_T^A-d/W$ curve for E-glass/epoxy composite plate with the geometrical defect of circular hole placed centrally. The plates were loaded to uniaxial direction for simplification. Finite element analysis (FEA) was carried out via ACP (ANSYS composite prepost module). Based on the least squares method, a simple expression of fitting equation could be given based on the simulated results of a set of discrete points. Finally, all three achievable solutions were presented graphically for explicit comparison. In addition, the investigation into customized efficient SCFs has also been carried out for further reference.