• Title/Summary/Keyword: Mechanical engineering

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Effect of fabrication processes on mechanical properties of glass fiber reinforced polymer composites for 49 meter (160 foot) recreational yachts

  • Kim, Dave Dae-Wook;Hennigan, Daniel John;Beavers, Kevin Daniel
    • 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.

  • https://doi.org/10.3744/JNAOE.2010.2.1.045 인용 PDF KSCI

Heat Transfer Characteristics of Aluminium and FeCrAlY Foam

  • Jin, Meihua;Kim, Pil-Hwan;Lee, Hae-Jong;Jeong, Hyo-Min;Chung, Han-Shik
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.395-401
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    • 2008

  • Since metallic foam will increase the performance of heat exchanger, it have caused many researcher's attention recently. Our research base on the model that metallic foams applied to heat exchanger. In this case, there is three kind of heat transfer mechanisms, heat conduction in fibers, heat transfer by conduction in fluid phase, and internal heat change between solid and fluid phases. In this paper we study both the hydraulic and thermal aspect performance. Pressure drop along air flow direction will be presented. As thermal aspect, we first discuss the acceptance of applying thermal equilibrium among the two phases. then to calculate the dimensionless temperature profile, the heat transfer coefficient and Nu number in 14 metallic foams(7 Aluminium foams, 7 FeCrAlY foams). All these discussion is based on the same velocity u=2 m/s.

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Microfactory for Electro-Chemical Machining (마이크로 전기${\cdot}$화학 복합형상 제거시스템)

  • Lee H.W.;Kook K.H.;Kim K.W.;Kim T.G.;Ryu B.H.;Jung J.W.;Han M.S.;Jung Y.H.;Min B.K.;Lee S.J.
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2005.05a
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    • pp.389-394
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    • 2005

  • Microfactory is effective method for machining micro size component. Electro-chemical machining can be more suitable to a microfactory than other machining methods in terms of maintaining high accuracy. Surface profile of EDM Machined component is predicted by micro EDM simulation using superpositioning spark crater. Planar motor and micro pump are developed to construct microfactory system.

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