• 제목/요약/키워드: Composite fraction

검색결과 712건 처리시간 0.03초

다공성 금속의 성형공정 후 열탄성 계수 (Thermoelastic Properties of Porous Metals After Material Forming Processes)

  • 이종원;김진원
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 추계학술발표대회 논문집
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    • pp.217-220
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    • 2003
  • The effective thermoelastic properties of porous metals are discussed herein after each material forming process such as hot pressing or extrusion. The voids in metal matrix are assumed to be initially spherical in shape and to be distributed randomly. Once the porous material deforms plastically due to each material forming process, the voids change their shape from a sphere to an ellipsoid and align in one direction. Since the voids are compressible in nature, the void volume fraction is assumed to be decreasing during each material forming process.

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복합재료의 평면전자파 차폐효과 (Electromagnetic Shielding Effectiveness of the Composite Materials in the Far Field Region)

  • 정연춘;강태원;정낙삼
    • 한국전자파학회지:전자파기술
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    • 제5권1호
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    • pp.31-39
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    • 1994
  • 다양한 복합재료의 평면 전자파 차폐효과를 플랜지형 동축선 측정치구를 사용하여 평가하였다. 이들 측정결과로부커 제품의 외장재로 사용할 다양한 차폐재료의 선택 우선순의를 결정할 수 있다. 전자파차폐기능 복합재료의 차페 성능은 재료에 포함된 급속분말이나 급속섬유의 종류와 함량에 크게 의존한며, 최적 함량의 결정과 최적 첨가재의 선택이 매우 중요함을 알았다.

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치과용 복합레진의 기계적 성질과 AE특성 (MECHANICAL PROPERTIES AND ACOUSTIC EMISSION CHARACTERISTICS OF DENTAL COMPOSITE RESINS)

  • 김교한;박진훈
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1990년도 추계학술대회
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    • pp.64-67
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    • 1990
  • Bending strength, bending elastic modulus ,and fracture toughness of different types of dental composite resins were deter mined. The relationship between bending strength, fracture toughness and filler volume fraction of dental composite resin was understood. In Acoustic Emission(AE) behavior during fracture toughness test, characteristic generation patterns of each type were understood. The fracture toughness values, AE generation patterns, and the nature of fracture surface were analyzed to understand fracture behavior of dental composite resin.

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폴리에틸렌기지 복합재료의 동적탄성계수에 대한 강화재의 효과 (Effect of Reinforcements on Dynamic Elastic Modulus of Polyethylene Matrix Composite Materials)

  • 김경섭;정현규;홍순형
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 1999년도 추계학술발표대회 논문집
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    • pp.1-4
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    • 1999
  • The attenuation coefficients of SiC particle reinforced low-density polyethylene (LDPE) matrix composites were measured by pulse echo method and dynamic elastic measure method with varying the volume fraction of SiC particle ranged from 0% to 40% and the size of SiC particles ranged from 0.8$\mu$m to 48$\mu$m. The SiCp/LDPE composites were fabricated with the melt injection process and the fabricated composites showed almost full density above 99% up to 40vo1% SiCp reinforcements. The attenuation constant of LDPE measured by dynamic elastic constant had same result with that measured by pulse echo method, but the attenuation constant of SiCp/LDPE measured by dynamic elastic constant did not have same result with that measured by pulse echo method.

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층간균열이 존재하는 균일 열유동하의 섬유강화 적층복합재료의 열응력해석 (Thermal Stresses in a Laminated Fiber-Reinforced Composite Containing an Interlaminar Crack Under a Uniform Heat Flow)

  • 최형집;오준성;이강용
    • 대한기계학회논문집
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    • 제18권4호
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    • pp.887-902
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    • 1994
  • Within the framework of anisotropic thermoelasticity, the problem of an interlaminar crack in a laminated fiber-reinforced composite subjected to a uniform heat flow is investigated. Under a state of generalized plane deformation, dissimilar anisotropic half-spaces with different fiber orientations are considered to be bound together by a matrix interlayer containing the crack. The interlayer models the matrix-rich interlaminar region of the fibrous composite laminate. Based on the flexibility/stiffness matrix approach, formulation of the current crack problem results in having to solve two sets of singular integral equations for temperature and thermal stress analyses. Numerical results are obtained, illustrating the parametric effects of laminate stacking sequence, relative crack size, crack location, crack surface partial insulation, and fiber volume fraction on the values of mixed mode thermal stress intensity factors.

Bending behavior of SWCNT reinforced composite plates

  • Chavan, Shivaji G.;Lal, Achchhe
    • Steel and Composite Structures
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    • 제24권5호
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    • pp.537-548
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    • 2017
  • In this paper presents bending characteristic of single wall carbon nanotube reinforced functionally graded composite (SWCNTRC-FG) plates. The finite element implementation of bending analysis of laminated composite plate via well-established higher order shear deformation theory (HSDT). A seven degree of freedom and $C^0$ continuity finite element model using eight noded isoperimetric elements is developed for precise computation of deflection and stresses of SWCNTRC plate subjected to sinusoidal transverse load. The finite element implementation is carried out through a finite element code developed in MATLAB. The results obtained by present approach are compared with the results available in the literatures. The effective material properties of the laminated SWCNTRC plate are used by Mori-Tanaka method. Numerical results have been obtained with different parameters, width-to-thickness ratio (a/h), stress distribution profile along thickness direction, different SWCNTRC-FG plate, boundary condition, through the thickness (z/h) ratio, volume fraction of SWCNT.

동기지 동계 Bulk Amorphous 복합재의 압축 변형거동 (Deformation behavior in Cu-based bulk amorphous alloys composite during compression)

  • 이창호;김지수;박은수;허무영
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2004년도 추계학술대회논문집
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    • pp.203-206
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    • 2004
  • Copper-based bulk amorphous alloy composite was synthesized by using the copper-coated $Cu_{54}Ni_{6}Zr_{22}Ti_{18}$ amorphous powder which was obtained by argon gas atomization. The amorphous powder having a super-cooled liquid region of 53 K was coated by crystalline copper by electroless coating. The consolidation was carried out by manufacturing performs and by the subsequent warm extrusion at 743 K. During the compression test at the room temperature, the composite containing a large fraction of crystalline copper displayed a larger plastic strain after yielding. FEM simulation revealed change in fracture modes in the composites depending on the amount of crystalline copper in the composites.

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용탕단조법에 의한 AC4A/SiCw 복합재료 제조에 관한 연구(III) - 기계적 특성 - (Fabrication of AC4A/SiCw composite by squeeze casting (III) - Mechanical characteristics -)

  • 문경철;이준희;윤의박
    • 열처리공학회지
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    • 제7권3호
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    • pp.160-168
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    • 1994
  • This was studied about mechanical characteristic of AC4A/SiCw 10-30% reinforced composites. Tensile strength of pressed base metal(base metal) with SiCw preform was higher than without pressed base metal(AC4A). If SiCw whisker volume fraction was increased, tensile strength at room temperature was increased. And tensile strength of SiCw 30% was about $35kg/mm^2$. Tensile strength of SiCw 30 % $400^{\circ}C$ at same time aging was the most excellence, about $40kg/mm^2$. The fracture energy value of composite material at three point bending test was higher than AC4A. Dislocation at matrix of composite material was evenly distributed. But dislocation around whisker of composite material was more existed than matrix. The reasom was thought of pile-up around whisker.

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합성재료 물성치의 수치적 예측 (Numerical Prediction of Mechanical Properties of Composites)

  • 신수봉;고현무
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1997년도 봄 학술발표회 논문집
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    • pp.11-18
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    • 1997
  • Mechanical properties of a composite mixed by components with known material properties are numerically predicted at various volume fractions rather than investigated through experiments. The properties, elastic modulus and Poisson's ratio, are estimated by minimizing the error between the static displacements computed from a model for the composite and those computed from a model of homogeneous and isotropic material. A finite element model for a composite is proposed to distribute different types of material components easily into the model depending on the volume fraction. Mechanical properties of a composite filled with solid mircospheres are predicted numerically through a sample study and the estimated results are compared with experimental results and some theories.

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Study on Metal/Diamond Binary Composite Coatings by Cold Spray

  • Kim, H.J.;Jung, D.H.;Jang, J.H.;Lee, C.H.
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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    • pp.240-241
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    • 2006
  • Metal/diamond binary composite coatings on Al substrate without grit blasting were deposited by cold spray process with insitu powder preheating. Microstructural characterization of the as-sprayed coatings with different diamond size, strength and with/without Ti coating on diamond was carried out by OM and SEM. The assessment of basic properties such as tensile bond strength and hardness of the coatings, and the deposition efficiency was also carried out. Particular attention on the composite coatings was on the diamond fracture phenomenon during the cold spray deposition and the interface bonding between the diamond and the Fe-based metal matrix.

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