• 제목/요약/키워드: Confinement

검색결과 1,223건 처리시간 0.024초

Phase Transition of Confined Gold Nanoparticles: Replica Exchange Molecular Dynamics Study

  • Kim, Hyun-Sik;Li, Feng-Yin;Jang, Soon-Min
    • Bulletin of the Korean Chemical Society
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    • 제33권3호
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    • pp.929-932
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    • 2012
  • The classical molecular dynamics simulation was used to study the phase transition of gold nanoparticles under confinement using Sutton-Chen (SC) potential. Metal gold nanoparticles with different number of atoms are subject to replica exchange molecular dynamics simulation for this purpose. The simulation showing the solidto-liquid melting temperature largely remains unaffected by confinement, while the confinement induces characteristic pre-melting at very low temperature depending on atom number in nanoparticles.

전단벽의 단부보강효과에 따른 변형능력의 평가 (Effect of Edge Confinement on Deformation Capacity in the Isolated R/C Structural Walls)

  • 이희동;한상환;이리형
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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    • pp.525-528
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    • 1998
  • This paper reports on tests of reinforced concrete shear walls for wall-type apartment structure under axial loads and the cyclic reversal of lateral loads with different confinement of the boundary elements. Confinement of the extreme element by U-stirrups and tie hooks seems to be as effective as closed stirrups. The shear strength capacity seems not to be increased by the confinement but deformation capacity improved.

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철근콘크리트 벽체 압축단부의 구속효과 (Confinement Effectiveness on Compressive Zone of RC Walls)

  • 김장훈;안상훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.459-464
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    • 2001
  • A great level of strength and deformability on compressive zone of RC wall is essentially required when subjected to high axial and in-plane lateral loading due to earthquakes. One of the best ways to handle this situation is to provide the confinement effectiveness to the compressive zone by reinforcing steel. For this a series of design charts were constructed to evaluate the confinement effectiveness for a given steel configuration in accordance with a well-known model and part of them are presented in this paper. Using the chart, designers can choose a desirable steel arrangement in flexural compressive zone of RC walls for a prescribed confinement factor.

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고강도 콘크리트 부재의 횡보강 효과에 관한 연구 (The Lateral Confinment Effects of Spiral Reinforcement of High Strength Concrete Columns.)

  • 신성우;권영호;이광수;오정근
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1989년도 가을 학술발표회 논문집
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    • pp.63-67
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    • 1989
  • Various studies have been done to investigate the effectiveness of lateral confinement of lower strength concrete(below 420kg/$\textrm{cm}^2$). But little research its effectiveness for high strength concrete. A certain concern has been arised that the beneficial effect of lateral confinement in high strength concrete may be different from that in lower strength. This study aimed to investigate that concern with different confinement spacing(D/2 : D/4). The results show that beneficial effects of spiral confinement are more pronounced for lower strength concrete as compared to higher strength concrete.

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대출력 글라스레이저에 의한 관성밀폐핵융합 (Inertial Confinement Fusion by High Power Glass Laser)

  • 강형부
    • 전기의세계
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    • 제28권11호
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    • pp.3-13
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    • 1979
  • 현재 전개되고 있는 핵융합연구는 크게 두가지 방식으로 구분할수 있다. 즉 자장밀폐(Magnetic confinement)방식 및 관성밀폐(Inertial confinement)방식으로 구분된다. 관성밀폐방식에 의한 핵융합연구는 자장밀폐핵융합연구보다 훨씬 늦게 시작되었지만 그에 비슷한 큰 성과를 나타내고 있다. 특히 대출려글라스레이저에 의한 관성밀폐핵융합연구의 성과가 연저하다. 본문에서는 이 글라스레이저에 의한 핵융합에 관하여 그 개요를 해설하기로 한다.

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철근콘크리트 교각의 연성도와 심부구속철근량의 상관관계 (Relationship between Ductility and Confinement Steel of RC Bridge Columns)

  • 손혁수;한상엽;이재훈
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2002년도 가을 학술발표회 논문집
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    • pp.141-146
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    • 2002
  • The purpose of this study is to develop a reasonable design for transverse confinement reinforcement considering ductility and required transverse confinement reinforcement of RC bridge columns. In order to develop relationships between the curvature ductility and required transverse confinement reinforcement for design purpose, the analysis using the computer program NARCC have been carried out for parametric studies. Based on the results from the parametric studies, an equation for calculating the required transverse confinement reinforcement based on ductility demand was developed for seismic design of RC bridge columns. The equations proposed by this study will provide more reasonable and more effective design guidelines for performance-based seismic design of RC bridge columns.

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Effect of confinement on flexural ductility design of concrete beams

  • Chen, X.C.;Bai, Z.Z.;Au, F.T.K.
    • Computers and Concrete
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    • 제20권2호
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    • pp.129-143
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    • 2017
  • Seismic design of reinforced concrete (RC) structures requires a certain minimum level of flexural ductility. For example, Eurocode EN1998-1 directly specifies a minimum flexural ductility for RC beams, while Chinese code GB50011 limits the equivalent rectangular stress block depth ratio at peak resisting moment to achieve a certain nominal minimum flexural ductility indirectly. Although confinement is effective in improving the ductility of RC beams, most design codes do not provide any guidelines due to the lack of a suitable theory. In this study, the confinement for desirable flexural ductility performance of both normal- and high-strength concrete beams is evaluated based on a rigorous full-range moment-curvature analysis. An effective strategy is proposed for flexural ductility design of RC beams taking into account confinement. The key parameters considered include the maximum difference of tension and compression reinforcement ratios, and maximum neutral axis depth ratio at peak resisting moment. Empirical formulae and tables are then developed to provide guidelines accordingly.

단부구속 효과에 따른 철근콘크리트 T형 벽체의 구조성능 평가에 관한 실험적 연구 (Experimental Study of Structural Capacity Evaluation of RC T-shape Walls with the Confinement Effect)

  • 하상수;윤현도;최창식;오영훈;이원호;이리형
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2001년도 가을 학술발표회 논문집
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    • pp.191-196
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    • 2001
  • The structural performance of a shear wall subjected to lateral loads is influenced by many factors, such as sectional shape, aspect ratio, vertical and horizontal reinforcement, lateral confinement and axial compression, etc. This experimental research is focusing to investigate the structural performance of T-shaped walls with different confining reinforcement. Experimental results show that all specimens finally failed by the crushing of the concrete in the compression zone. Although the location and content of the lateral confinement is different, the results are very similar during the negative loading direction where the flange is compressed. However, when flange is subjected to tension, the location and content of the lateral confinement results in a large difference in the structural performance of T-shaped walls. Therefore, selection of location and content of the lateral confinement would be important aspect in the design of the nonsymmetric structural walls.

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횡구속 영향을 고려한 부착 및 정착길이 설계 개선 안 (Proposed Design Provisions for Bond and Development Length Considering Effects of Confinement)

  • 최완철;김상준
    • 콘크리트학회논문집
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    • 제11권5호
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    • pp.61-68
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    • 1999
  • Confinement is one of the major concepts for bond of reinforcing steel to concrete. Cover distance, and lateral reinforcement are the key factors for current provisions for development and splices of reinforcement. However, the current provisions still being complicated to calculate major variables need to be developed in the process of design. In this study, an experimental work was performed to examine the behavior of bond using beam end specimens. The test results and previous available data are analyzed to isolate the effects of confinement on bond strength. From this reevaluation, new provisions for development and splice of reinforcement are proposed. The provisions also propose some limits for confinement index. The new provisions will help engineers to decide easily the simple but conservative way for manual calculations or the exact approach for computerized design.

전단보강이 있는 강섬유 보강 고강도 철근콘크리트 보의 전단 및 연상에 관한 연구 (Shear Strenhth and Ductility of Steel-Fiber Reinforced High Strength Concrete Beams with Shear Confinement)

  • 오정근;이광수;권영호;신성우
    • 콘크리트학회지
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    • 제2권4호
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    • pp.53-60
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    • 1990
  • 전단보강된 고강도콘크리트 보의 역학적 거동을 알아보기 위하여 총9개의 시험체가 제작되었다. 콘크리트 압축강도가 800kg/$\textrm{cm}^2$ 전단스팬비가 3 그리고 주근비가 0.5Pb로 일정할 때 주요변수로서 전단보강비(Vs=0,25,50%)와 섬유첨가율(Vf=0,0.5,1%)로 두었다. 시험결과로 섬유첨가율의 증가에도 극한강도의 변화는 별반 없었으나 연성 능력을 향상시켰으며, 전단보강철근으로의 대체성을 보여주었다.