• 제목/요약/키워드: Brittle

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철근콘크리트 보의 보강용 연성 하이브리드 FRP 시트의 특성 (Properties of Ductile Hybrid FRP Sheet for Strengthening of Reinforced Concrete Beams)

  • 송형수;이진용;민창식
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.509-510
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    • 2009
  • FRP 시트를 사용한 철근콘크리트 보의 보강은 섬유의 선형 응력-변형률 거동으로 인한 취성파괴 가 일어난다. 본 연구에서는 두 가지 섬유를 사용하여 하이브리드 FRP 시트를 연구하였다.

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Poly(lactic acid)/Poly($\varepsilon$ -caprolactone) 블렌드의 열적 특성

  • 윤철수;지동선
    • 한국섬유공학회:학술대회논문집
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    • 한국섬유공학회 1998년도 봄 학술발표회 논문집
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    • pp.67-70
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    • 1998
  • 지방족 폴리에스테르계 고분자인 Poly(lactic acid)(PLA)는 생분해성, 생체적합성, 분해물의 비독성, 가공성 등이 우수하여 부러진 뼈의 접합 재료, 약물 조절 방출 재료 및 흡수성 봉합사 등과 같은 의료용 소재로 널리 이용되고 있다[1]. 그러나 PLA는 높은 결정화도로 인해 물성이 brittle하고 분해속도가 느릴 뿐만 아니라 낮은 열 안정성으로 인해 용융 가공할 경우 급격한 분자량의 감소를 유발하여 기계적 특성이 좋지 않은 단점이 있다.(중략)

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재생골재를 이용한 폴리프로필렌 섬유보강콘크리트의 강도 및 휨인성 특성연구 (Characteristics of the Strength and Toughness of Polypropylene Fiber Reinforced Concrete using Recycled Aggregates.)

  • 류택은;박재성;조영래;오희보;구봉근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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    • pp.655-660
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    • 2000
  • This study was performed to verify the properties of concrete used recycled aggregate(0, 30%, 50%). Also, to improve the brittle fracture, energy absorption and apparent ductility of concrete, we added polypropylene fibers(0, 0.1, 0.2, 0.5, 1.0% by volume of concrete). As the experimental results, adding 30% recycled aggregates and 0.5% polypropylene fibers to concrete mixes enhances the properties of both compressive strength and toughness.

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기존 교각의 FRP 원통관을 이용한 내진보강의 실험연구 (The Experimental Study on the Seismic Strengthening Effect of FRP Circular Tube on the Circular Bridge Piers)

  • 황윤국;윤순종;김정호;최영민;박경훈;권태규
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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    • pp.973-978
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    • 2003
  • This paper describes the experimental study on seismic strengthening effect of circular bridge columns with poor lap-splice details using FRP(Fiber Reinforced Plastic) wrapping, The as-built column suffered brittle failure due to the deterioration of lap-spliced longitudinal reinforcement without developing its flexural capacity or any ductility, The strengthening columns using FRP wrapping showed significant improvement in seismic performance due to FRP's confinement effect.

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The Mechanical Properties of Alkali Resistance Glass Fiber Reinforced Cement under Different Curing Conditions

  • Jeong, Moon-Young;Song, Jong-Taek
    • The Korean Journal of Ceramics
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    • 제4권3호
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    • pp.189-192
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    • 1998
  • The mechanical properties of alkali resistance (AR) glass fiber reinforced cement(GFRC) under different curing conditions were investigated in this study. The specimens were formed by extrusion process, and then steam cured and autoclaved. An autoclaved specimen showed the elastic-brittle behavior up to 4% of fiber volume fraction. However, it was found that the fracture behavior for cured specimen was changed to the elastic-plastic with crack branches fracture at greater than 3 vol.% of fiber.

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MgO.$P_2O_5$ 유리의 기계적 성질에 미치는 수분의 영향 (Effects of Water on Mechanical Properties of Magnesium Metaphosphate Glass)

  • 강은태;박용완
    • 한국세라믹학회지
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    • 제23권5호
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    • pp.75-80
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    • 1986
  • The mechanical properties were measured for magnesium phosphate glasses containing small amounts of water. The decrease in hardness with increasing water content was resulted from a looser chain structure caused by water. The fracture of these glasses was changed from brittle fracture to plastic deformation as a results of the increased viscous flow with increasing water contents. The extent of any viscous flow or deformation initiating from the crack tips in these glasses could be considered as quite small.

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업셋팅 을 이용한 냉간압접 에 대한 연구 (Study on the cold pressure welding by upsetting)

  • 안기원;김재도
    • Journal of Welding and Joining
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    • 제3권2호
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    • pp.27-34
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    • 1985
  • The mechanical properties and bonding mechanism of aluminum, copper and mild steel have been determined in cold pressure welding. The brittle cover layer to be established by scratch-brushing plays an important role in bond strength and has an influence on the threshold of deformation. The cold pressure welding was achieved at 54% of height reduction in A1-A1, 75% in Cu-Cu, 56% in Al-Cu, and 74% in Cu-steel. The height reduction at which the bond strength of weld interface was the same as the tensile strength of base metal should be over 76% in Al-Al, 82% in Cu-Cu, and 78% in Al-Cu.

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무전해 Ni위에 형성된 Sn-Ag-Cu솔더 접합부의 계면 금속간화합물 변화 및 접합부 취성파괴 거동 연구 (Study of Interfacial Intermetallic Compounds and Brittle Fracture Behavior of Sn-Ag-Cu Solder on Electroless Plated Nicke)

  • 유세훈;김경호;서원일;한덕곤;이태호
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2015년도 추계학술대회 논문집
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    • pp.231-231
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    • 2015
  • 무전해 Ni의 Metal turnover (MTO)가 증가함에 따라, Ni과 Sn-Ag-Cu솔더간 계면 금속간화합물층의 두꺼워지고, Ni-Sn-P층에 형성된 Nano void의 수가 많아지게 되어 취성파괴가 증가한다.

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Microstructure, mineralogy and physical properties: techniques and application to the Pusan Clay

  • Locat, Jacques;Tanaka, Hiroyuki
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 1999년도 준설 및 환경매립에 관한 학술세미나
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    • pp.15-31
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    • 1999
  • The Pusan Clay is analyzed hereafter from a point of view of mineralogy and microstructure. Results indicate that the Pusan Clay is basically illitic in nature and that the soil microstructure reveals some characteristics which could be responsible for its brittle behavior as observed from sample disturbance. The overall analysis would tend to consider that the Pusan Clay profile analyzed here shows mechanical properties similar to well structured soils or so-called cemented soils.

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