• 제목/요약/키워드: Composite Material

검색결과 5,075건 처리시간 0.036초

우주항공용 탄소/에폭시 복합재료의 기계적 특성 평가에 관한 고찰 (A Study on the Mechanical Property Evaluation of Carbon/Epoxy Composite Material for Aerospace Application)

  • Lee, Ho-Sung;Min, Kyung-Ju
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2003년도 추계학술발표강연 및 논문개요집
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    • pp.149-149
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    • 2003
  • This paper presents the work peformed in a program developing composite material which properties satisfy structural and thermal requirements for aircrafts and spacecrafts. In the aerospace vehicle structures, the specific strength of the materials is one of the important requirements and this is why polymer matrix composite material with reinforced carbon fiber is widely used. However, the mechanical properties of the composite material have been known to be dependent on processing and this difficulties in evaluation have caused a lot of mechanical tests for each batch.

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설계요구조건 검증을 통한 한국형 고속 틸팅열차(TTX)의 차체 재료 선정에 관한 연구 (A Study on Material Selection of the Carbody Structure of Korean Tilting Train express(TTX) through the Verification of Design Requirements)

  • 신광복;구동회;한성호;박기진
    • 한국철도학회논문집
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    • 제7권2호
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    • pp.77-84
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    • 2004
  • In order to determine the most suitable material system for achieving the lightweight design while fulfilling the design requirements of carbody structures of Korean Tilting Train eXpress(TTX), aluminum carbody. composite carbody, and hybrid carbody combined with aluminum and composite structures were considered in the present study. The finite-element analysis was used to verify the design requirements or the TTX carbody structures with the material system considered in the design stages. The stresses in the carbody structures and deflections of underframe against static load cases were used as design criteria. The results show that the hybrid carbody structures are beneficial with regard to weight savings and structural integrity in comparison to aluminum and composite carbody structures.

광섬유 브래그 격자 센서를 이용한 고온용 복합재의 물성 측정 (Measurement of Material Properties of Composites for High Temperature using Fiber Bragg Grating Sensors)

  • 강동훈;박상욱;김수현;김천곤;홍창선
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2003년도 춘계학술발표대회 논문집
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    • pp.31-36
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    • 2003
  • Recently, composite materials are widely used for nozzle, pressure vessel, skins of satellite and many structures under condition of high temperature due to good thermal characteristics such as low CTE, heat-resistance, etc. Fiber optic sensors, especially FBG(fiber Bragg grating) sensors, can be a good counterproposal of strain gages for the measurement of material properties of composites under high temperature. In this research, T700/Epoxy specimens with embedded FBG sensors were fabricated and tested at the Instron with thermal chamber from room temperature to $400^{\circ}C$. The effects of embedding optical fiber on material properties were also verified. And, the experimental results were discussed and analyzed by microphotographs of the composite specimen.

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인장하중에 따른 Carbon/Carbon복합재의 진동특성 (The Vibration Characteristic of Carbon-Carbon Composite Material due to Tensile Loading)

  • 오승규;곽이구;김홍건
    • 한국생산제조학회지
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    • 제20권6호
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    • pp.740-744
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    • 2011
  • Carbon-carbon composite material is the reinforced carbon fiber. Because of its high strength, elasticity and the excellent heat-resisting property in high temperature, carbon-carbon composite material has been used in many fields such as aerospace and automotive industries, etc. Especially, aircraft brake discs used at aerospace can be cracked due to its fatigue and vibration under various loading condition. This research is focused on the influence of the vibration of carbon-carbon composite material by using accelerometer with impact hammer excitation. And the change of vibration mode will be known by applying tensile loading test.

균질화 접근법을 통한 복합재의 유효물성치 계산 (Effective Material Properties of Composite Materials by Using a Numerical Homogenization Approach)

  • 아닉 다스 안토;조희근
    • 한국기계가공학회지
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    • 제18권12호
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    • pp.28-37
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    • 2019
  • Due to their flexible tailoring qualities, composites have become fascinating materials for structural engineers. While the research area of fiber-reinforced composite materials was previously limited to synthetic materials, natural fibers have recently become the primary research focus as the best alternative to artificial fibers. The natural fibers are eco-friendly and relatively cheaper than synthetic fibers. The main concern of current research into natural fiber-reinforced composites is the prediction and enhancement of the effective material properties. In the present work, finite element analysis is used with a numerical homogenization approach to determine the effective material properties of jute fiber-reinforced epoxy composites with various volume fractions of fiber. The finite element analysis results for the jute fiber-reinforced epoxy composite are then compared with several well-known analytical models.

경량화 CFRP 부재의 휨 강도와 강성 특성 (The Characteristics of Flexure Strength and Rigidity in Light-weight CFRP Members)

  • 양인영;김정호;김지훈
    • 한국정밀공학회지
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    • 제25권11호
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    • pp.95-99
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    • 2008
  • Applications of composite materials in various engineering fields have been extended significantly. For being useful composite materials, we could modify the rigidity and strength characteristics of composite material according to structures and material direction. In this study, CFRP, which has been widely used in space leisure and general structural applications due to the weight, elasticity coefficient, high fatigue strength and lower thermal transformation ect, was selected. As the CFRP is an anisotropic material whose mechanical properties change with its stacking sequence or angle, special attention was given to the effects of the fiber orientation angle on the bending characteristics of CFRP fiat and CFEP square members. It's different on the each result of strength and rigidity of CFRP flat and CFRP square members.

충진 모형실험을 통한 NATM Composite 라이닝 터널 뒤채움재의 기포손실 최소화를 위한 적정 이송거리 고찰 (A Study on the Proper Transfer Distance for Minimizing Air Flotation Loss of Backfilling Material of NATM Composite lining Tunnel in the Model Test)

  • 마상준;최희섭;이흥수;김경덕
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2008년도 추계 학술발표회
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    • pp.1555-1558
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    • 2008
  • In this paper, result of whole test, When the Transfer Distance is increasing, Strength of Backfilling Material of NATM Composite lining Tunnel due to increasing Gravity was increased, but that is higher the Air Flotation than increasing Strength. So, That was predicted a drop of Permeability. And Performing the placing Lightweight Foamed Mortar, we think that it's performance in drain material was lost. Therefore We conclude that Proper Transfer Distance that taking Permeability through minimizing of Air Flotation Loss and getting the Need Strength is 50m.

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한국형 고속 틸팅열차(TTX)의 차체 재질 선정 연구 (A Study on Material Selection of the Carbody Structure of Korean Tilting Train eXpress(TTX))

  • 신광복;구동회
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.462-467
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    • 2004
  • In order to determine the most suitable material system which can achieve the lightweight design and fulfill the design requirements of carbody structures of Korean Tilting Train eXpress (TTX), aluminum carbody, composite carbody, and hybrid carbody combined with aluminum and composite structures were considered in present study. The finite-element analysis was used to verity the design requirements of the TTX carbody structures with the material system being considered in the design stages. The stresses in the carbody structures and deflections of underframe against static load cases were checked as design criteria. The results show that the hybrid carbody structures are beneficial with regard to weight savings and structural integrity when compared to aluminum and composite carbody structures.

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적층각도가 다른 단방향 CFRP와 SM45C샌드위치형 복합재료에 관한 융합적 연구 (Convergence Study on Composite Material of Unidirectional CFRP and SM 45C Sandwich Type that Differs in Stacking Angle)

  • 박재웅;조재웅
    • 한국융합학회논문지
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    • 제8권7호
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    • pp.231-236
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    • 2017
  • 본 연구에서는 고분자재료인 CFRP(Carbon Fiber Reinforced Plastic)과 구조용 금속인 SM45C로 이루어진 이종 복합재료가 경량화 재료용으로 사용되고 있다. SM45C를 심재로 갖고 양면에 섬유 적층각도가 다른 단반향 CFRP를 접착시킨 샌드위치형 복합재료를 이용하여 CT(Compact Tension)시험을 기초로 한 유한요소 해석을 진행하였다. CT시험은 하중을 받는 재료내의 크랙으로 인한 파괴거동을 확인하기 위한 대표적인 방법이다. 이종 복합재료를 기계 구조물에 적용하기 위해서는 크랙 및 구멍에 대한 영향을 연구하여야 한다. 샌드위치형 복합재료의 CT시험에 의한 파괴거동을 시뮬레이션 해석으로 연구하였다. 본 연구 결과로서, [0/60/-60/0]의 적층각도를 가진 단방향 CFRP 샌드위치형태 복합재료가 우수한 강도를 갖으며 최대 등가응력은 약 182GPa정도가 나타났다. 또한 복합 재료 형상으로서의 디자인적 요소를 융합 기술에 접목함으로서 그 미적인 감각을 나타낼 수 있다.

복합재료 경화도 측정을 위한 유전 센서 (Dielectric sensor for cure monitoring of composite materials)

  • 김학성;권재욱;김진국;이대길;최진경;김일영
    • 한국복합재료학회:학술대회논문집
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    • 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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    • pp.219-223
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    • 2001
  • The on-line cure monitoring during the cure process of composite materials is important for better quality and productivity. The dielectric sensor for cure monitoring consists of base film and electrodes. Because the characteristic of dielectric sensor for the on-line cure monitoring is dependent on the base material, width and number of electrode, etc, the dielectric sensor should be standardized. And the selection of base film material of sensor is very important. In order to prevent the measuring errors generated from the increase of environmental temperature, the base film material should have stable dielectric constant with respect to environmental temperature. In this study, the newly developed dielectric sensor for cure monitoring was designed and the dissipation factor which is function of degree of cure was measured using the sensor. The relationship between the dissipation factor and degree of cure with respect to environmental temperature was investigated.

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