• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.57-60
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• 2005

Composite-to-aluminum joins were tested to get failure loads and modes for three types of joins; adhesive bonding, bolt fastening, and adhesive-bolt hybrid joining. Film type adhesive FM73 and paste type adhesive Cytec EA9394S were used for aluminum and composite bonding to make a double-lap joint. A digital microscope camcorder was used to monitor the failure initiation and propagation. It was found that the hybrid joining is an effective method to strengthen the joint when the mechanical fastening is stronger than the bonding as in the case of using the paste type adhesive. On the contrary, when the strength of the bolted joint is lower than the strength of the bonded joint as in the joint with the film type adhesive, the bolt joining contribute little to the hybrid joint strength.

• Aerospace Engineering and Technology
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• v.6 no.1
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• pp.1-6
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• 2007

The present study provides the compressive design allowable of a unidirectional glass/epoxy composite laminate processed by wet lay-up at room temperature. The compressive strength values measured from 39 specimens have been assumed to follow the two-parameter Weibull distribution. Following the statistical guidelines provided by MIL-HDBK-17F, the B-basis and A-basis values of the aforementioned laminate are found to be 82.6% and 65.9%, of the mean compressive strength, respectively. The B-basis value is then discounted further at 50% for the in-situ application on the main wing spar caps of an experimental canard aircraft.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1996.05a
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• pp.219-226
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• 1996

일반적으로 밀폐 형단조공정에서 약 10,000톤의 성형력이 필요한 직경이 540mm인 플랜지 형태의 알루미늄 7175 합금 단조품을 2,500톤 프레스에서 단조하기 위한 공정연구를 하였다. 장비의 성형력 부족을 극복하기 위하여 업셋단조와 기계가공 및 전방압출을 조합한 복합성형공정을 제안하였으며, 복합공정은 실제재료를 이용한 $\frac{1}{4}$ 축소 모델 실험과 유한 요소 해석으로 그 타당성이 판단되었고, 선정된 프레스에서 실물 크기의 플랜지 단조 가능성을 확인하였다.

• Korean Chemical Engineering Research
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• v.46 no.1
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• pp.7-14
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• 2008

Carbon nanotubes are considered as the most ideal nano filler in the field of composites with their excellent electrical, mechanical, and thermal properties. Therefore carbon nanotubes composites are increasingly utilized in conductive materials, structural material with high strength and low weight and multifunctional material. This review article describes recent research trend of carbon nanotubes synthesis, modification, various properties of the carbon nanotubes composites and their application. Furthermore the future development direction for the commercialization of carbon nanotubes composites is proposed.

• Composites Research
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• v.33 no.6
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• pp.401-407
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• 2020

At the engineering and industrial areas, the lightweight composite material has been substituted with the metals, such as steel at the structural parts. This composite material has been applied by the adhesive bonding method, as well as the joint methods with rivets, welds or bolts and nuts. The study on the strength characteristics of adhesive interface is necessarily required in order to apply the method to composite materials. CFRP specimens as the fiber reinforced plastic composites were manufactured easily and this study was carried out. The static experiments were performed under the loading conditions of in-plane and out-plane shears with the inhomogeneous composite TDCB specimens with CFRP, aluminum (Al6061), and aluminum foam (Al-foam). Through the result of this study, the durability on the inhomogeneous composite structure with adhesive interface was investigated by examining the fracture characteristic and the point in time.

• Polymer(Korea)
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• v.29 no.4
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• pp.375-379
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• 2005

The morphology and therma]/viscoelastic characteristics were investigated for PLLA/MMT nanocomposite manufactured by incorporating inorganic nanosized silicate nanoplatelets into biodeuadable poly(l-lactic acid) (PLLA). The XRD difiactogram and TEM image may be regarded as a formation of homogeneously dispersed nanocomposites. The melting energy(${\Delta}H_m$) was increased during hydrolysis process because of increase of crystallinity. As MMT played a role of reinforcing agent, the storage modulus was increase in case of PLLA/MMT nanocomposite, it was well coincided with our previous results. From SEM image, many tiny pinholes formed by spinodal decomposition were observed on the surface, and the shape of nanocomposite was maintained during hydrolysis process. In this study, it was shown that the control of biodegradation rate, thermal/mechnical property was possibile by incorporating MMT.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.04a
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• pp.143-148
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• 2000

In this article, we presents multi-objective design optimization of laminated composite beam using Fuzzy programming method. At first, the two design objectives are minimizing the structural weight and maximizing the buckling load respectively. Fuzzy multi-optimization problem can be formulated based on results of single optimizations. Due to different relative importance of design objectives, membership functions are constructed by adding exponential parameters for different objective's weights. Finite element analysis of composite beam for buckling behavior are carried by Natural mode method proposed by J.Argyris and computational time of analysis can be reduced. With this scheme, a designer can conveniently obtain a compromise optimal solution of a multi-objective optimization problem only by providing some exponential parameters corresponding to the importance of the objective functions.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.16 no.7 s.112
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• pp.762-768
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• 2006

To address the need for new intelligent sensing of systems, this study presents a novel strain sensor based on piezoresistivity of carbon nanotube (CNT) and its nanocomposites. Fabrication and characterization of the carbon nanocomposite material are discussed and an electrical model of the CNT strain sensor was derived based on electrochemical impedance spectroscopy analysis and strain testing. The dynamic response of the sensor on a vibrating beam was simulated using numerical analysis and it was compared with experimental test. The simulation showed good agreement with the strain response of the actual sensor.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.930-935
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• 2006

To address the need for new intelligent sensing of systems, this study presents a novel strain sensor based on peizoresistivity of carbon nanotube (CNT) and its nanocomposites. Fabrication and characterization of the carbon nanocomposite material are discussed and an electrical model of the CNT strain sensor was derived based on electrochemical impedance spectroscopy analysis and strain testing. The dynamic response of the sensor on a vibrating beam was simulated using numerical analysis and it was compared with experimental test. The simulation showed good agreement with the strain response of the actual sensor.

• Applied Chemistry for Engineering
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• v.26 no.3
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• pp.239-246
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• 2015

The hybridization of carbon nano-materials enhances the efficiency of each function of the resulting structure or composites. Also, the addition of non-carbon elements to nanomaterials modifies the electrochemical properties. Electrodes combining porous carbon nanofibers (CNFs) and metal oxides benefit from the combination of the double-layer capacitance of the CNFs and the pseudocapacitive character associated with the surface redox-type reactions. Consequently, they demonstrate superior supercapacitor performance in terms of high capacitance, high energy/power efficiency and high rate capability. This paper presents a comprehensive review of the latest advances made in the development and application of various metal oxide/CNF composites (CNFCs) to supercapacitor electrodes.