• 제목/요약/키워드: Ultra-high temperature condition

검색결과 81건 처리시간 0.032초

고온 및 재하에 따른 초고강도콘크리트의 변형거동 (Strain Behavior of Ultra-high-strength Concrete under High Temperature and Loading)

  • 김규용;남정수;최경철;윤민호;황의철;백재욱
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.86-87
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    • 2017
  • The high-temperature creep of Ultra-High-Strength Concrete (UHSC) has been investigated in this study. The purpose of this study is to evaluated total strain and high-temperature creep at elevated temperatures under loading condition of UHSC. As results, Total strain of UHSC increased showing shrinkage with increasing compressive strength. The high-temperature creep of UHSC increased with the temperature and higher level of compressive strength showed bigger high-temperature creep.

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가열 및 하중조건에 따른 초고강도콘크리트의 과도변형 (Transient Creep Strain of Ultra High Strength Concrete with Heating and Loading)

  • 최경철;김규용;윤민호;이영욱;황의철;유재철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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    • pp.59-60
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    • 2015
  • In this study, stress-strain, thermal expansion strain, total strain and high temperature creep strain of ultra-high-strength concrete with compressive strengths of 80, 130, and 180MPa were experimentally evaluated considering elevated temperature and loading condition. Also, transient creep strain has been calculated by using the results of experiment. Experimental coefficient K was proposed with application of non-steady state creep model. It is considered that the experimental results of this study could be baseline data for deformation behavior analysis of ultra-high-strength concrete.

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에폭시 경화물 DSC에 의한 유리전이 온도 측정의 분석조건 의존성 (The Effect of DSC Analysis Condition on the Glass Transition Temperature of curred Epoxy This paper studies on the effect of DSC(Differential Scanning Calorimeter) analysis condition on the glass transition temperature of silica filled epoxy network polymer used for ultra-high voltage apparatus. The effects of temperature scanning rate specimen size and gas flow rate on measured glass transition temperature have been studied in order to select optimum thermal analysis condition.)

  • 오무원;권혁삼
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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    • pp.30-33
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    • 1994
  • This paper studies on the effect of DSC(Differential Scanning Calorimeter) analysis condition on the glass transition temperature of silica filled epoxy network polymer used for ultra-high voltage apparatus. The effects of temperature scanning rate specimen size and gas flow rate on measured glass transition temperature have been studied in order to select optimum thermal analysis condition.

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Bead Formation and Wire Temperature Distribution during Ultra-high-speed GTA Welding Using Pulse-heated Hot-wire

  • Shinozaki, K.;Yamamoto, M.;Mitsuhata, Koichi;Nagashima, Toshiharu;Kanazawa, T.;Arashin, H.
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2009년 추계학술발표대회
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    • pp.226-234
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    • 2009
  • The purpose of this study was to investigate the melting phenomenon of filler wire in detail and to obtain the precise temperature distribution of filler wire during GTA welding under the ultra-high welding speed condition in order to develop the ultra-high-speed GTA welding process with the pulse-heated hot-wire system by using three kinds of materials. The melting phenomenon of filler wire was observed using a high-speed camera and the temperature distribution of filler wire was measured using a radiation thermometer. From the above result, the adequate welding conditions of each material to make the GTA welding process with the ultra-high welding speed could be obtained. The ultra-high-speed GTA welding process needed the adequate wire current in order to obtain the adequate temperature distribution and the adequate melting position of filler wire. Moreover, the temperature distributions of three kinds of filler wire could be estimated by using the proposed simple estimation method.

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하중재하조건을 고려한 초고강도 콘크리트의 열변형거동특성 평가 (Evaluation on Thermal Strain Behavior Properties of Ultra High Strength Concrete considering Load)

  • 이영욱;김규용;최경철;김홍섭;이보경;윤민호
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 추계 학술논문 발표대회
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    • pp.162-163
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    • 2015
  • Thermal deformation behavior of high-strength concrete (HSC) exposed to fire is different from that of normal strength concrete (NSC). In case of ultra-high-strength concrete (UHSC), it is well known that thermal deformation behavior is greater than HSC. With increasing research of UHSC in buildings, it is necessary to understand the performance of UHSC at elevated temperatures considering loading condition. Therefore, evaluation on properties of thermal strain behavior properties of ultra high strength concrete by loading and high temperature was conducted.

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하중재하조건을 고려한 초고강도 콘크리트의 열변형거동특성 평가 (Evaluation on Thermal Strain Behavior Properties of Ultra High Strength Concrete considering Load)

  • 이영욱;김규용;최경철;김홍섭;이보경;윤민호
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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    • pp.80-81
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    • 2015
  • Thermal deformation behavior of high-strength concrete (HSC) exposed to fire is different from that of normal strength concrete (NSC). In case of ultra-high-strength concrete (UHSC), it is well known that thermal deformation behavior is greater than HSC. With increasing research of UHSC in buildings, it is necessary to understand the performance of UHSC at elevated temperatures considering loading condition. Therefore, evaluation on properties of thermal strain behavior properties of ultra high strength concrete by loading and high temperature was conducted.

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가열조건에 따른 초고강도 콘크리트의 내부수증기압력 평가 (Evaluation on Vapor Pressure of Ultra-high-strength Concrete by Heating Condition)

  • 황의철;김규용;윤민호;이보경;서원우;백재욱
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2017년도 춘계 학술논문 발표대회
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    • pp.224-225
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    • 2017
  • Ultra-high-strength concrete exposed to high temperature is likely to cause spalling. Spalling is caused by the vapor pressure of the concrete, and the vapor pressure may be different depending on the heating conditions of the concrete. Therefore, in this study, a ring-type restrained specimen was fabricated using ultra-high-strength concrete and the vapor pressure generated in the concrete by heating condition(rapid and slow heating) was evaluated.

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설계하중 및 고온을 받은 초고강도 콘크리트의 잔존압축강도 및 변형 특성 평가 (Evaluation on Residual Compressive Strength and Strain Properties of Ultra High Strength Concrete with Design Load and Elevated Temperature)

  • 윤민호;김규용;남정수;윤종일;배창오;최경철
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2012년도 추계 학술논문 발표대회
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    • pp.263-264
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    • 2012
  • In this study, the ultra high strength concrete which have 100, 150, 200MPa took the heat from 20℃ to 70 0℃ and the 0, 20% stress in normal condition's to evaluate stress-strain, residual compressive strength and thermal expansion deformation were evaluated. The heating speed of specimen was 0.77℃/min 20~50℃, 50℃ before the target temperature, and the other interval's heating speed was 1℃/min. As a result, the stress-strain curve of non-load specimen showed the liner behavior at high temperature when the specimen's strength increased more. If ultra high strength concrete got loads, its compressive strength tended to decrease different from the normal strength concrete. The thermal expansion deformation was expanded from a vitrification of quartz over 500℃. however, over the 600℃, it was shrinked because of the dehydration of the combined water.

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저온소결을 통한 초고용량 MLCC 개발 (Development of Ultra-high Capacitance MLCC through Low Temperature Sintering)

  • 손성범;김효섭;송순모;김영태;허강헌
    • 한국세라믹학회지
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    • 제46권2호
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    • pp.146-154
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    • 2009
  • It is necessary to minimize the thickness of Ni inner electrode layer and to improve the coverage of inner electrode, for the purpose of developing the ultra high-capacity multi layered ceramic capacitor (MLCC). Thus, low temperature sintering of dielectric $BaTiO_3$ ceramic should be precedently investigated. In this work, the relationship between dielectric properties of MLCC and batch condition such as mixing and milling methods was investigated in the $BaTiO_3$(BT)-Dy-Mg-Ba system with borosilicate glass as a sintering agent. In addition, several chip properties of MLCC manufactured by low temperature sintering were compared with conventionally manufactured MLCC. It was found that low temperature sintered MLCC showed better DC-bias property and lower aging rate. It was also confirmed that the thickness of Ni inner electrode layer became thinner and the coverage of inner electrode was improved through low temperature sintering.

최적 가공 조건 선정을 위한 300mm 웨이퍼 폴리싱의 가공특성 연구 (The Study on the Machining Characteristics of 300mm Wafer Polishing for Optimal Machining Condition)

  • 원종구;이정택;이은상
    • 한국공작기계학회논문집
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    • 제17권2호
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    • pp.1-6
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    • 2008
  • In recent years, developments in the semiconductor and electronic industries have brought a rapid increase in the use of large size silicon wafer. For further improvement of the ultra precision surface and flatness of Si wafer necessary to high density ULSI, it is known that polishing is very important. However, most of these investigation was experiment less than 300mm diameter. Polishing is one of the important methods in manufacturing of Si wafers and in thinning of completed device wafers. This study reports the machining variables that has major influence on the characteristic of wafer polishing. It was adapted to polishing pressure, machining speed, and the slurry mix ratio, the optimum condition is selected by ultra precision wafer polishing using load cell and infrared temperature sensor. The optimum machining condition is selected a result data that use a pressure and table speed data. By using optimum condition, it achieves a ultra precision mirror like surface.