• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1990.10a
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• pp.137-142
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• 1990

본 연구에서는 유한요소법을 사용하여 이방성으로 적층된 평판의 고유모드 를 예측하고, 이론적인 예측의 정확성을 연구하기 위해 사변 단순지지의 다 양한 각도로 적층된 정사각형 CFRP평판의 8번째 진동모드까지 실험적인 결 과와 비교하였다. 이 연구에서 사용된 모든 평판은 중앙면에 대칭이며, 이것 은 Bundling-stretching coupling을 제거하기 위해서이다. 그러나 만일 비대 칭적으로 적층된 평판이라면 이 효과를 포함한 해석이 되어야 할 것이다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.199-204
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• 1998

In this study, a method is presented which can be used to measure the fiber orientation distribution for thickness direction during injection molding using image processing. The intensity method in used for measuring the distribution. And the effects of fiber content, injection molding condictions on the orientation function are also discussed.

• Composites Research
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• v.12 no.5
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• pp.23-30
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• 1999

Fiber reinforced composite materials are widely used in automotive industry to produce parts that are large, thin, lightweight, strong and stiff. It is very important to know a charge shape in order to have good products in the compression molding. In particular, the product such as a bumper beam is composed of the random and unidirectional fiber mats. The characteristics of flow fronts such as a bulging phenomenon for random mat and unidirectional fiber mat and slip parameters are studied numerically. And the effects of viscosity ratio and stack type on mold filling parameters are also discussed.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.10a
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• pp.176-181
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• 1997

During a compression molding of continuous fiber reinforced composites, the separation of matrix and fiber is caused by the flow of the molding process. As the characteristics of the products are greatly dependent on the separation, it is very important to clarify the separation in relation to molding condition, degree of needle punching number on the degree of nonhomogeneity are studied.

• Transactions of the Korean Society of Automotive Engineers
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• v.6 no.4
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• pp.32-38
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• 1998

In order to investigate the relationship between the stiffness and structure of the automotive roof panels, two kinds of glass fiber reinforced plastic(GFRP) roof panels without and with insert material were fabricated by resin transfer molding(RTM) method. The stiffness test was performed at the same condition as it of actual driving. The structural design and material selection for improving the recyclability of GFRP roof panels were also covered.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.05a
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• pp.173-178
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• 2002

Fourier transform has been one of the most common tools to study the frequency characteristics of signals. With the Fourier transform alone, it is difficult to tell whether signal's frequency contents evolve in time or not. Except for a few special cases, the frequency contents of most signals encountered in the real world change with time. Time-frequency methods are developed recently to overcome the drawbacks of Fourier transform, which can represent the information of signals in time and frequency at the same time. In this study, heat damage process of a carbon fiber reinforced plastic(CFRP) and glass fiber reinforced plastic(GFRP) under monotonic tensile loading was characterized by acoustic emission. Different kinds of specimens were used to determine the characteristics of Strength and AE signals. Time-frequency analysis methods were employed for the analysis of fracture mechanism in CFRP such as matrix cracking, debonding and fiber fracture.

• Composites Research
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• v.23 no.1
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• pp.31-36
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• 2010

The improvement of electrical conductivity of carbon-fiber reinforced plastics (CFRP) has been investigated by silver nano-particles coating for the purpose of lightning strike protection. Silver nano-particles in colloid were sprayed on the surface of carbon fibers, which were then impregnated by epoxy resin to form a CFRP specimen. Electrical resistance was measured by contact resistance meter which utilize the principles of the AC 4-terminal method. Electrical resistance value was then converted to electrical conductivity. The coated silver nano-particles on the carbon fibers were verified by SEM and EDS. The electrical conductivity was increased by three times of the ordinary CFRP.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.920-925
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• 2012

A study of vehicle weight lightening has been progressed to reduce the fuel consumption. In this paper, the body floor in an EV (Electric Vehicle) bus has been applied by composites as CFRP and GFRP. In order to analyse a various reliability and safety, an experiment and FEM analysis was carried out to obtain weight lightening. Especially, the joint. An effective design is obtained through an experiment as well as FEM analysis. Results of stress analysis of GFRP material showed twice as much displacement than those of CFRP material. Among three kinds of joint methods, the bond joint method is occurred to a substantial shape change in the body and floor. It is found that the rivet joints are fairly suitable for stress sustaining capability.

• Composites Research
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• v.27 no.3
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• pp.103-108
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• 2014

Fiber reinforced polymer plastic (FRP) structural members are recently available in construction industries due to various material properties such as high specific strength and stiffness, light-weight, and corrosionresistance. The floating PV generation structure can also be an illustration for applying FRP in construction applications. The floating PV generation structure has been recently issued as a representative item for the low carbon and green growth campaign and many related studies have been conducted for the structural safety and commercial viability. Moreover, the floating PV generation structures for the commercial purpose have been constructed. In this paper, the investigation and development processes of elements for the floating PV generation structure are presented during commercialization.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11b
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• pp.373-376
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• 2003

본 연 구에서 얻어진 결과 제조업체별 수집한 합성피혁, 섬유, 플라스틱, 폴리우레탄, 실리콘수지등의 MBT, DBT의 농도는 대략 0 - 1000 ${\mu}g$/kg 정도의 분포를 나타내었고 TBT는 0-500 ${\mu}g$/kg 정도의 분포를 나타내었다. 그리고 전체적으로 합성피혁, 실리콘수지, 플라스틱 & 폴리우레탄, 천 등의 순으로 높게 검출 되었다. 이결과는 우리가 현재 가장 밀접하게 접하고 있는 신발, 스포츠의류, 가죽의류 등의 제품에서 유기주석 화합물의 인체에 미치는 유해성 대해서는 선진국에서 규제하는 수준에는 부합된다는 것을 보여준다. 갈수록 선진국에서 환경인증에 대 한 요구를 강화함에 따라 국제적 환경인증 마크인 ‘에코텍스 스텐더드(Oeko-tex standard) 100’ 에서는 다음과 같이 규제하고 있다. TBT, DBT의 두 화합물로 기준치는 TBT의 경우, Product Class I은 0.5 ppm. II, III, IV의 경우는 1.0 ppm이며, DBT 는 Product Class I(유아용) 에만 해당하고 1.0 ppm이다. 우리나라도 대부분의 선진국처럼 유기 주석 화합물의 사용을 적극 억제하는 등 법적인 장치 가 마련돼야 한다고 여겨진다. 또한 유독성의 유기주석 촉매 대체물질로서 환경 친화형인 즉, MBT, DBT, TBT가 전혀 함유되지 않은 무독성의 유기금속촉매를 개발하는데 노력을 기울여 야 할 것이다.