• Title/Summary/Keyword: Composite material

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Composite Material made of Recycling Paper and Plastics (폐지를 활용한 재생 플라스틱)

  • 윤승원;이장용;김윤식
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.697-702
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    • 2002
  • Composite material made of recycling paper and plastics was developed. The tension and bending testing result of developed composite material shows that the cellulose contained in paper contributes much to get high flexural rigidity. As an application example, the raised access floor for office automation purpose was developed by making use of developed composite material. Manufacturing process together with the extrusion die and the compression die for to manufacture the access floor have been developed.

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복합재료 적층판의 유한요소법 기반 역학적 거동 해석

  • Im, Yeong-Nam;Cheon, Jae-Hui;Lee, Ho-Seong
    • Proceeding of EDISON Challenge
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    • pp.285-291
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    • 2015
  • In this paper, a composite material analysis program based on the finite element method(FEM) is used. The purpose of this study was to verify whether the composite material analysis program which developed as part of a project of development of softwares and educational contents for structural vibration and composite material analysis that can calculate how similar the macroscopic mechanical behavior of the composite materials actually. Because composite materials are generally anisotropic, analysis of composite laminate is used for the constitutive equations of orthotropic material. For convenience, the unit is ommited in all calculations. To verify the accuracy of the finite element method based program, the deflection and stress distribution of the simply supported composite material laminated plate subjected to a uniform load distribution is compared with exact solution. Size and properties of the composite material laminate used for analysis are fixed variables, and by changing the number of elements and the total thickness of the laminate is compared with the exact solution to the resulting value, respectively.

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Precise Drilling characteristics of glass fiber epoxy composite material (유리섬유 에폭시 복합재료의 정밀드릴가공 특성)

  • 김홍배
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.4
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    • pp.117-122
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    • 1998
  • Glass fiber epoxy composite material is widely used in the structures of aircrafts, robots and other machines because of their high specific strength, high specific stiffness and high damping. In order for the composite materials to be used in the aircraft structures or machine elements, accurate surfaces for bearing mounting or joint must be provided, which require precise machining. In this paper, the machinability of the glass fiber epoxy composite material was experimentally investigated. The results can be summarized as follows : 1. The entrance of hole is very good manufacturing existing, but exit come to occur sever surface exfoliation. 2. The cutting force in drilling of the glass fiber epoxy composite material is decreased as the drilling speed increased. 3. If the glass fiber epoxy composite material is drilling by the standard twist drill, then the hole recommand cutting condition is spindle speed 400∼600rpm, feed 40∼50mm/min.

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The Influence of Repeated Loading Cycles on Strength Ratio of Carbon/Epoxy Composite Laminates (Carbon/Epoxy 복합재료 적층판의 반복하중에 따른 강도계수의 변화에 대한 연구)

  • Kim, Doo-Hwan;Kim, Young-Feel
    • Journal of the Korean Society of Safety
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    • v.24 no.3
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    • pp.19-24
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    • 2009
  • Currently the technique of composite material field is developed day by day. The many kinds industrial facility and life articles are coming to make with the composite material. But still the engineering works field the building and the bridge uses the material which is old era and is making. To here there is a various problem but the biggest problem the theory of the composite material is complicated too and means that the application is been delayed about constructive structure. When the composite material is used widely from constructive field, too with difficult theory in technical expert and easily with the research for the experiment data accumulation is necessary. The tensile and fatigue test of the carbon/epoxy which is a high-class composite material led from the present paper consequently and the change of the intensity coefficient which follows in repeated load researched.

The Evaluation of Fracture Toughness of SMC Composite Material and Carbon/Epoxy Composite Material (SMC 복합재료와 Carbon/Epoxy 복합재료의 파괴인성평가)

  • 최영근;이유태;이태순
    • Journal of Ocean Engineering and Technology
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    • v.7 no.1
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    • pp.25-32
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    • 1993
  • In composite materials, the fracture perpendicular to the fiber direction usually shows a non-linear behavior accompannying blunting and plastic deformation around the crack tip. In this study, the fracture thoughness in random short fiber SMC composite material and Carbon/Epoxy composite material is estimated by the A.M.(Area Method) and the G.L.M.(Generalized Locus Method) which can determine a stable total energy release rate(G$_T$) not only in highly elghly elastic material but also in highly non-linear materials.

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A Study on Optimal Design of Composite Materials using Neural Networks and Genetic Algorithms (신경회로망과 유전자 알고리즘을 이용한 복합재료의 최적설계에 관한 연구)

  • 김민철;주원식;장득열;조석수
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • pp.501-507
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    • 1997
  • Composite material has very excellent mechanical properties including tensile stress and specific strength. Especially impact loads may be expected in many of the engineering applications of it. The suitability of composite material for such applications is determined not only by the usual paramenters, but its impactor energy-absorbing properties. Composite material under impact load has poor mechanical behavior and so needs tailoring its structure. Genetic algorithms(GA) is probabilistic optimization technique by principle of natural genetics and natural selection and neural networks(NN) is useful for prediction operation on the basis of learned data. Therefore, This study presents optimization techniques on the basis of genetic algorithms and neural networks to minimum stiffness design of laminated composite material.

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Production & Performance Assessment of Composite Material Flexible Propeller (복합재료 유연 프로펠러의 제작 및 성능 평가)

  • Lee, Sang-Gab;Byun, Joon-Hyung;Paik, Bu-Geun;Hyun, Beom-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.6
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    • pp.667-674
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    • 2009
  • The researches on the development of composite material underwater vehicle propeller have been actively attempted for the reduction of radiation noise with outstanding damping effects. Composite material propellers have almost been designed and produced by the foreign experts, and it is difficult to obtain the related informations about their flow, vibration, material characteristics because they are treated as the secrets with close relationship to the military technology, especially in the case of underwater vehicles. For the security of domestic manufacture of composite material propeller and the comparison and examination of its performance and radiation noise characteristics with those of German CONTUR composite material propeller, two propellers were self-produced according to the fiber weaving and array using compressible molding process and their self performances and radiation noise characteristics were measured. The mean fluctuations of blade tip of self-produced composite material propeller were increased and the radiation noises in the low frequency band were reduced compared to those of CONTUR, which could be estimated as the change of material characteristics and also be thought to be used for the future research informations.

A Study on the Stress Analysis for Design of Composite Material Shafts of Small Boats (소형 선박용 복합재료 축 설계를 위한 음력해석에 관한 연구)

  • Kim, Yun-Hae;Im, Cheol-Mun;Bae, Chang-Won;Wang, Ji-Seok
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.2
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    • pp.308-313
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    • 2002
  • It is known that the composite material shafts using on small boats have various advantages comparing to forged steel shafts, fur examples, specific strength, fatigue strength, corrosion, etc. The analysis of the stresses and strains in the composite material shafts made by filament winding method is presented in this paper. The classical laminated plate theory is applied on the patch cut from the composite material hollow shafts. It is verified that the composite material hollow shafts of diameter 40 mm is the most optimum when the ratio of the inner diameter to the outer is 0.4 and winding angle is 45$^{\circ}$. It is also proven that the shear strain does not change seriously between 30$^{\circ}$and 60$^{\circ}$of winding angles. It is dangerous when the winding angle is over 75$^{\circ}$because the values of shear strain and stress produced on the shaft are too high so it must be avoided to wind the filament by the angle over 75$^{\circ}$.

Research on Aircraft Lightning Protection Design and Certification of Fuel System in Composite Material (복합재항공기 연료시스템의 낙뢰보호설계 및 인증 연구)

  • Lee, Young-jae;Cho, Wonil;Jeon, Jeonghwan;Koh, Jinhwan
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.25 no.4
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    • pp.130-140
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    • 2017
  • Lightning protective design of an aircraft fuel system is closely related to the safety of the flight. Recently, composite material in building an aircraft becomes more important because it can reduce the weight of the aircraft. The composite materials decrease the protection against the effect of lightning. Lightning protective design of metal material aircraft has been researched for a long time and the design technique has been announced widely. However, research on the lightning protective design using composite material aircraft is very limited. In this study, lightning protective design for fuel tank structural component, access cover, fuel filler cap and drain valve in carbon fiber composite material aircraft have been presented. To show the compliance with FAA airworthiness standard regarding the presented protection designs, three steps, including lightning strike analysis, lightning environment analysis and certification test, were conducted in accordance with FAA AC 20-53.

Synthesis of TiB2 Dispersed Cu Matrix Composite Material by the Combination of the Mechanical Milling and Plasma Activated Sintering Process (기계적 밀링과 플라즈마 활성 소결법에 의한 TiB2 분산 Cu기 복합재료 제조)

  • Kim, Kyong-Ju;Lee, Gil-Geun;Park, Ik-Min
    • Journal of Korean Powder Metallurgy Institute
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    • v.14 no.5
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    • pp.292-297
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    • 2007
  • The present study was focused on the synthesis of a $TiB_2$ dispersed copper matrix composite material by the combination of the mechanical milling and plasma activated sintering processes. The $Cu/TiB_2$ mixed powder was prepared by the combination of the mechanical milling and reduction processes using the copper oxide and titanium diboride powder as the raw material. The synthesized $Cu/TiB_2$ mixed powder was sintered by the plasma activated sintering process. The hardness and electric conductivity of the sintered bodies were measured using micro vickers hardness and four probe method, respectively. The relative density of $Cu/TiB_2$ composite material sintered at $800^{\circ}C$ showed about 98% of theoretical density. The $Cu-1vol%TiB_2$ composite material has a hardness of about 130Hv and an electric conductivity of about 85% IACS. The hardness and electric conductivity of $Cu-3vol%TiB_2$ composite material were about 140 Hv and about 45% IACS, respectively.