• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.9-10
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• 2017

For the structural analysis of reinforced concrete structures, the mechanical properties of concrete at each temperature are required and the mechanical property values according to specific temperature are presented in the design regulations and codes. In this study, the mechanical properties of concrete were experimented by using 35MPa concrete produced in Korea from 20℃ to 900℃(two kinds of test method). Compared the results with previous domestic papers, we aimed to contribute to the construction of mechanical characteristics D.B. of at the elevated temperatures of domestically produced concrete which can be used for structural analysis in fire.

• International Journal of Naval Architecture and Ocean Engineering
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• v.2 no.1
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• pp.45-56
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• 2010

Polymer composite materials offer high strength and stiffness to weight ratio, corrosion resistance, and total life cost reductions that appeal to the marine industry. The advantages of composite construction have led to their incorporation in U.S. yacht hull structures over 46 meters (150 feet) in length. In order to construct even larger hull structures, higher quality composites with lower cost production techniques need to be developed. In this study, the effect of composite hull fabrication processes on mechanical properties of glass fiber reinforced plastic (GFRP) composites is presented. Fabrication techniques investigated during this study are hand lay-up (HL), vacuum infusion (VI), and hybrid (HL+VI) processes. Mechanical property testing includes: tensile, compressive, and ignition loss sample analysis. Results demonstrate that the vacuum pressure implemented dining composite fabrication has an effect on mechanical properties. The VI processed GFRP yields improved mechanical properties in tension/compression strengths and tensile modulus. The hybrid GFRP composites, however, failed in a sequential manor, due to dissimilar failure modes in the HL and VI processed sides. Fractography analysis was conducted to validate the mechanical property testing results.

• Corrosion Science and Technology
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• v.17 no.2
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• pp.81-89
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• 2018

In this study, the effect of Nb alloying element on the corrosion fatigue properties of high strength steel is investigated by conducting fatigue experiments under corrosive condition and hydrogen induced condition, potentiodynamic polarization test, tensile test and surface analyses. Nb element is added to enhance the mechanical property of medium carbon steel. This element forms MX-type phases such as carbides and nitrides which are playing an important role in the grain refinement. The grain refinement is one of the effective way to improve mechanical property because both tensile strength and toughness can be improved at the same time. However, MX-type phase precipitates can be a susceptible site to localized corrosion in corrosive environment due to the potential difference between matrix and precipitate. The obtained results showed that Nb-added steel improved corrosion fatigue property by grain refinement. However, it is degraded for hydrogen-induced fatigue property due to Nb, Ti-inclusions acting as a stronger trap.

• Journal of Power System Engineering
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• v.15 no.1
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• pp.45-50
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• 2011

The effect of Mn and Ti contents in filler wire on the microstructure and mechanical property of weld metal has been investigated after hybrid welding with ultra fine grained (UFG) steel. The microstructure and distribution of alloy compositions at the top region of weld zone were quite different with those at the bottom region after hybrid welding. The bottom region of weld zone contained higher Mn and Ti contents, and consequently the hardness of bottom region was higher than that of top region. With the increase of Mn and Ti contents in filler wire, the volume percent of acicular ferrite in weld metal decreased, and the weld zone showed higher hardness and better impact property.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.3 s.258
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• pp.403-408
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• 2007

The concrete pipe(Hume, PC) and polyethylene(PE) pipe are usually used for dram pipe in local market. Hume pipe, however, is heavy and needs the high cost of construction and PC pipe has a disadvantage to easily occur the deformation by the outside pressure even though it is light and constructible. The corrugated steel pipe coated with polyethylene is used increasedly because it is durable, constructible and economical. However, it is not used for sewage or waste water because it is hard to guarantee the watertight property on the coupling part. In this study, we studied on the flange coupling and the method of its construction to guarantee the watertight property and easy to use. If the developed flange coupling and method are used on a construction field, the economical property, constructible property and structural safety can be guaranteed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.243-244
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• 2007

The improvement of critical current property as well as the mechanical property is important for the application. The improvement of the critical current can be achieved by forming the nano size defect working as a flux pining center inside the superconductor. The nano size defect can be effectively formed by using neutron iradiation. All properties of most of materials after irradition become bad On the contrary, the critical current property of the superconductor is largely improved after irradiation.

• Proceedings of the Korean Magnestics Society Conference
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• 2008.12a
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• pp.314.2-314.2
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• 2008

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.1008-1016
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• 2014

This study aims to analyze the changes in the mechanical properties of woven fabrics(cotton, linen, wool, silk, and polyester) by bonding fusible interlinings with varying deniers(10D, 20D, and 30D) for a 3D virtual try-on system(one that a user to try garments through screens using Avatar) developed over the last decade. We experimented with four mechanical properties and thicknesses of twenty-three specimens of interlining bonded fabrics including face fabrics and interlinings by using the KES-FB-AUTO system. The results showed that the tensile property increased(LT and RT increased and WT decreased) as the denier of the interlining increased; however, the change was slight. In contrast, the bending and shear properties increased significantly as the denier of the interlining increased on both the warp and the weft. This showed evidence that the interlining gives the fabrics size stability. The compression property was slight changed as the tensile property varies depending on the fibers and the denier of interlining. As expected, the thickness increased by bonding the interlining as the denier of interlining increased. From these results, we conclude that 3D users need to reflect these changes of woven fabrics by bonding interlinings when they try screen fittings to accurately express the fabric reality of manufactured garment.

• Journal of the Korean Society for Heat Treatment
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• v.31 no.1
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• pp.12-17
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• 2018

We investigated the corrosion behavior of commercially pure cold working processed (CP)-Ti with coarse-grained (CG) microstructure heat-treated at $400^{\circ}C$ and $600^{\circ}C$, respectively. It is observed that corrosion resistance of as-received CP-Ti heat-treated at $400^{\circ}C$, at which recrystallization proceeds, is largely improved. Interestingly, the mechanical property of CP-Ti sample at $400^{\circ}C$ was scarcely deteriorated. It is attributed to the decrease of the defects such as strain variance and dislocation density. On the other hand, the annealing treatment at $600^{\circ}C$ of CP-Ti plate causes to grain growth with the noticeable reduction of mechanical property. Hence, it is considered that defect density such as strain and dislocation density is important microstructural parameter for the improvement of corrosion resistance. The introduction of proper annealing treatment can help to improve corrosion resistance without scarifying mechanical property of CP-Ti.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.208-211
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• 2003

In this paper, mechanical property of electric epoxy with water aging was discussed. We studied mechanical property of elastic resin after absorption in water from 0 to 484 hour. As a result, diffusion factor of elastic epoxy showed $20-21{\times}10^{-4}mm^2/s$ and general epoxy showed $9.5{\times}10^{-4}mm^2/s$. Elastic property increased linearly according to amount of addictives and decreased elastic property according to amount of water absorption. Tensile strength was reduced to add to addictives. It was effected by water absorption of micro-void of elastic epoxy. Hardness inclined to decrease after increasing according to absorbed time.