• Title/Summary/Keyword: Multifunctional composite

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A Study on Impact Performance of Rubber-Filled Sandwich Composite (Rubber-Filled 샌드위치 복합재료의 충격 특성 연구)

  • Huang Hao;Joe Chee-Ryong;Kim Dong-Uk
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.10a
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    • pp.65-68
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    • 2004
  • A new multifunctional sandwich composite was investigated in this paper. The honeycomb core of this composite was filled with viscoelastic material in order to obtain an improved impact performance. The fillings in the honeycomb cells was hoped to provide the act of energy dissipation in this combined material system. Low-velocity drop-weight test was set up to the specimens with various stacked carbon/epoxy laminate facesheets, $[0/90]_{4s},\;[0/45/-45/90]_{2s}$. Load and energy history were checked and compared for the both groups of specimens, with and without rubber fillings. Further, the damaged faces were inspected visually by ultrasonic C-scan.

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Structural analysis of circular UHPCC form for hybrid pier under construction loads

  • Wu, X.G.;Zhao, X.Y.;Han, S.M.
    • Steel and Composite Structures
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    • v.12 no.2
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    • pp.167-181
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    • 2012
  • Ultra high performance cementitious composite material is applied to the design of multifunctional permanent form for bridge pier in this paper. The basic properties and calculating constitutive model of ultra high performance cementitious composite are introduced briefly. According to momental theory of thin-walled shell, the analytical solutions of structural behavior parameters including circumferential stress, longitudinal stress and shear stress are derived for UHPCC thin-walled circular tube. Based on relevant code of construction loads (MHURD of PPC 2008), the calculating parameter expression of construction loads for UHPCC thin-walled circular tube is presented. With geometrical dimensions of typical pier, the structural behavior parameters of UHPCC tube under construction loads are calculated. The effects of geometrical parameters of UHPCC tube on structural behavior are analyzed and the design advices for UHPCC tube are proposed. This paper shall provide a scientific reference for UHPCC permanent form design and UHPCC hybrid structure application.

Bioinspired Nanoengineering of Multifunctional Superhydrophobic Surfaces

  • Choi, Chang-Hwan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2015.11a
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    • pp.102-133
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    • 2015
  • Nature, such as plants, insects, and marine animals, uses micro/nano-textured surfaces in their components (e.g., leaves, wings, eyes, legs, and skins) for multiple purposes, such as water-repellency, anti-adhesiveness, and self-cleanness. Such multifunctional surface properties are attributed to three-dimensional surface structures with modulated surface wettability. Especially, hydrophobic surface structures create a composite interface with liquid by retaining air between the structures, minimizing the contact area with liquid. Such non-wetting surface property, so-called superhydrophobicity, can offer numerous application potentials, such as hydrodynamic drag reduction, anti-biofouling, anti-corrosion, anti-fogging, anti-frosting, and anti-icing. Over the last couple of decades, we have witnessed a significant advancement in the understanding of surface superhydrophobicity as well as the design, fabrication, and applications of superhydrophobic coatings/surfaces/materials. In this talk, the designs, fabrications, and applications of superhydrophobic surfaces for multifunctionalities will be presented, including hydrodynamic friction reduction, anti-biofouling, anti-corrosion, and anti-icing.

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Enhancing Mechanical and Electrical Performance through Polymer Blending: A Study on PVA-PDDA Blended Films for Triboelectric Energy Harvesting

  • Nebiyou Tadesse Debele;Alemtsehay Tesfay Reda;Yong Tae Park
    • Composites Research
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    • v.37 no.2
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    • pp.139-142
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    • 2024
  • This study explores the impact of polymer blending on the mechanical properties and triboelectric energy harvesting capability of composite polymers. A multifunctional free-standing polymer blend composed of poly(vinyl alcohol) (PVA) and poly(diallyldimethylammonium chloride) (PDDA) was fabricated using a polymer casting method. Stress-strain analysis of the polymer blend revealed an enhanced stretchability of 308.4% with excellent transparency. Furthermore, triboelectric analysis revealed dynamic energy harvesting capabilities with impressive electrical voltage and current output of 50 V and 5 μA. These results represent a significant improvement compared to individual PVA and PDDA polymers and highlight the potential of polymer blending to enhance both mechanical and electrical properties for energy harvesting applications.

Study on the Improvement of Epoxy Property for Aluminum Conductor Composite Core (복합재료 중심인장선용 에폭시 물성 개선 연구)

  • Heo, Seok-Bong;Kang, Junyoung;Youn, Young-Gil;Goh, Munju;Kim, Nam Hoon
    • Composites Research
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    • v.32 no.6
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    • pp.349-354
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    • 2019
  • The Aluminum conductor composite core consists of fast-curing thermosetting epoxy used as reinforcements and carbon fiber and glass fiber used as matrix. In this study, we have investigated fast curing epoxy cured products used for composite core(Aluminum Conductor Composite Core, ACCC). Tetrafunctional epoxy(PA 806) was used as a multifunctional epoxy, along with two kinds of curing agents, MNAn(5-Methyl-5-norbornene-2,3-dicarboxylic anhydride) and HHPA(Hexahydrophthalic Anhydride), to make an epoxy cured product and their properties were evaluated. Optimum conditions are confirmed by varying the content of curing accelerator in the selected epoxy and curing agent.

Glass-alumina Composites Prepared by Melt-infiltration: Ⅰ. Effect of Alumina Particle Size (용융침투법으로 제조한 유리-알루미나 복합체: Ⅰ. 알루미나 입도 효과)

  • Lee, Deuk-Yong;Jang, Ju-Woong;Kim, Dae-Joon;Park, Il-Seok;Lee, Jun-Kwang;Lee, Myung-Hyun;Kim, Bae-Yeon
    • Journal of the Korean Ceramic Society
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    • v.38 no.9
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    • pp.799-805
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    • 2001
  • Two commercial alumina powders having different particle size of $0.5{\mu}m$ and 3${\mu}$m were presintered at 1120$^{\circ}$C for 2h and then lanthanum aluminosilicate glass was infiltrated at 1100$^{\circ}$C for up to 4h to obtain the densified glass-alumina composites. The effect of alumina particle size on packing factor, microstructure, wetting, porosity and pore size, and mechanical properties of the composite was investigated. The optimum mechanical properties and compaction behavior were observed for the 3${\mu}$m alumina particle dispersed composite. The 3${\mu}$m alumina particle size and distribution for he preform were within 0.1 to 48${\mu}$m and bimodal and random orientation. The strength and the fracture toughness of the composite having 3${\mu}$m alumina particles were 519MPa and $4.5MPa{\cdot}m^{1/2}$, respectively.

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Vibration and Stability of Composite Cylindrical Shells Subjected to Electromagnetic and Thermal Fields (자기장 및 열하중을 받는 복합재료 원통셸의 진동 및 안정성해석)

  • Park, Sang-Yun;Kang, Sunghwan;Seo, Jung Seok;Song, Ohseop
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.23 no.9
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    • pp.797-805
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    • 2013
  • In this paper vibration and stability analysis of laminated composite shells based on the first order shear deformation theory(FSDT) for two different boundary conditions(clamped-clamped, simply supported) are performed. Structural model of cross-ply symmetric laminated composite cylindrical shells subjected to a combination of magnetic and thermal fields is developed via Hamilton's variational principle. These coupled equations of motion are based on the electromagnetic equations(Faraday, Ampere, Ohm, and Lorenz equations)and thermal equations which are involved in constitutive equations. Extended Galerkin method is adopted to obtain the discretized equations of motion. Variations of dynamic characteristics of composite shells with applied magnetic field, temperature gradient, laminate thickness-ratio and radius ratio for two boundary conditions are investigated and pertinent conclusions are derived.

Spray Drying of Zirconia/Alumina Composite Powder Using PVP as a Binder (PVP 결합제를 이용한 지르코니아/알루미나 복합분말의 분무건조)

  • Shim, Hyung-Bo;Moon, Joo-Ho;Kim, Dae-Joon
    • Journal of the Korean Ceramic Society
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    • v.39 no.5
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    • pp.446-451
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    • 2002
  • Zirconia/alumina mixture powder was spray-dried various degree of dispersion, type of dispersants and powder content in the slurry. The quality of the granule was determined by observation of the granule shapes after spray drying and fracture of intergranular boundaries during pressing. Defect-free granules were obtained from the powders that formed weak flocs in the slurry. The granules, spray-dried from the slurry containing 32.5 vol% powder mixture and PVP as binder, were fractured completely during shaping and the sintered specimens showed a density of 99.7% and a flexural strength of 850 MPa.

Thermoelastic static and vibrational behaviors of nanocomposite thick cylinders reinforced with graphene

  • Moradi-Dastjerdi, Rasool;Behdinan, Kamran
    • Steel and Composite Structures
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    • v.31 no.5
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    • pp.529-539
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    • 2019
  • Current paper deals with thermoelastic static and free vibrational behaviors of axisymmetric thick cylinders reinforced with functionally graded (FG) randomly oriented graphene subjected to internal pressure and thermal gradient loads. The heat transfer and mechanical analyses of randomly oriented graphene-reinforced nanocomposite (GRNC) cylinders are facilitated by developing a weak form mesh-free method based on moving least squares (MLS) shape functions. Furthermore, in order to estimate the material properties of GRNC with temperature dependent components, a modified Halpin-Tsai model incorporated with two efficiency parameters is utilized. It is assumed that the distributions of graphene nano-sheets are uniform and FG along the radial direction of nanocomposite cylinders. By comparing with the exact result, the accuracy of the developed method is verified. Also, the convergence of the method is successfully confirmed. Then we investigated the effects of graphene distribution and volume fraction as well as thermo-mechanical boundary conditions on the temperature distribution, static response and natural frequency of the considered FG-GRNC thick cylinders. The results disclosed that graphene distribution has significant effects on the temperature and hoop stress distributions of FG-GRNC cylinders. However, the volume fraction of graphene has stronger effect on the natural frequencies of the considered thick cylinders than its distribution.