• Title, Summary, Keyword: 파열실험

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Evaluation of Bursting Behavior in Anchorage Zone of PSC I Girders (PSC I 거더의 정착부 파열거동 평가)

  • Choi, Kyu Chon;Park, Young Ha;Paik, In Yeol
    • Journal of The Korean Society of Civil Engineers
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    • v.30 no.3A
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    • pp.329-336
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    • 2010
  • An experimental study to evaluate bursting behavior in anchorage zone of the standard PSC I girders (span length : 30 m) has been carried out. The arrangement of bursting reinforcement in anchorage zone of the standard PSC I girders is considered to be designed without accurately reflecting the stress flows in the end zone of the PSC I girders caused by presstressing forces of the tendons. Also, due to excessive arrangement of the bursting bars, the workability of the girder is decreased greatly. In this study, three specimens with the same dimensions as the end zone of the standard PSC I girder are prepared and the experiment is carried out by applying PS forces. The bursting reinforcement of each specimen consists of 100 mm, 200 mm, and 300mm spacings, respectively. The experimental results show that the range of the PS forces to cause crack in the anchorage zone of the specimen are more than 1.6 times of the design PS forces. The bursting cracks occur in the vertical direction on the inside of all specimens. After applying 2.7 times of the design PS force, some of the transverse bursting reinforcements only in the specimen reinforced by 300 mm spacing yielded. The experimental results show that the anchorage zone of the standard PSC I girders arranged by 300 mm spacing of the bursting reinforcements which is the maximum spacing allowed in the road bridge design specifications, can be considered safe enough.

A study of osteonectin expression patterns in BAPN-induced cleft palate formed rats (BAPN으로 유도된 구개파열 백서의 osteonectin발현 양상에 대한 연구)

  • Tae, Ki-Chul;Kim, En-Chel;Lee, Sun-Kyeong
    • The korean journal of orthodontics
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    • v.30 no.4
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    • pp.433-440
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    • 2000
  • The purpose of this study was to investigate osteonectin expression patterns in cleft palate compare to normal palate rats. We used 4 pregnant rats, and beta-aminoproprionitrile was oral dose to rat according to 1g/kg body weight at gestation days 13 to induce cleft palate. Total 6 fetus was got with cleft formed, then 3 fetus was used for immunohistostain and 3 fetus was used for western blot analysis. Expression patterns of osteonectin in mesenchymal cells of cleft palate was more dilute to mesenchymal cells of normal palate with immnunohistostain, and width and length of band of maxilla in cleft palate was more thin than maxilla of normal palate with western blot study.

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An Experimental Study on the Potable hot plates used with Butane Gas (카세트식 이동식부탄연소기의 사용에 관한 실험적 연구)

  • 이근오;이장우
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • pp.207-214
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    • 1999
  • 카세트식 이동식부탄연소기의 사고는 과열에 의한 화재뿐만 아니라 접합용기의 파열에 따른 피해가 더 큰 위험성을 내포하고 있다. 접합용기의 파열원인은 화재에 의한 파열과 접합용기 장착 불량에 의한 가스누출로 화염에 의한 파열, 그리고 과대 조리기구를 사용하여 조리기구 및 화염에서 발생되는 열이 접합용기에 전달되어 온도상승에 따른 파열로 구분된다. 현재 카세트식 이동식부탄연소기의 조리기구 크기에 따라 과열에 따른 정확한 검증이 부족하며, 사용자에게 사용장소와 조리기구외 크기만 권고하고 있어 이에 대한 자료가 필요하다. (중략)

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An Evaluation on Rupture Behavior of Nozzle Closure in Multi-Nozzle System (멀티노즐시스템의 노즐마개 파열 거동 분석)

  • Ro, Young-Hee
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.42 no.9
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    • pp.745-751
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    • 2014
  • For the multi-nozzle propulsion, the rupture pressure of nozzle closure has an effect on the initial strain rate of ignition. Moreover, the deviation of rupture pressure for each nozzle closure leads to side forces which can disturb the attitude control of rocket. When designed, it should be considered whether nozzle closures are ruptured equally and exactly in the intented pressure. In this paper, the rupture behavior is analyzed by analytical and experimental methods for plate and "+" notched nozzle closures. The rupture pressure and deviation for operating temperature, whether notched or not and notched directions are analyzed. This paper provides a comparison between rupture pressure prediction of finite elements method which tool is Abaqus/Explicit and results of the rupture test. Jonson-Cook shear failure model which corresponds to the damage initiation criterion were used in this simulation.

Analysis of Burst Detection Based on Adjustable Sampling Interval (가변적 샘플링 기반한 누수탐지 분석)

  • Kim, Seong Won;Jeong, An Chul;Jung, Kwan Sue
    • Proceedings of the Korea Water Resources Association Conference
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    • pp.292-292
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    • 2015
  • 최근 상수관망의 물 공급 과정에서 여러 가지 원인으로 인해 물의 손실에 따른 비용손실이 발생하고 있다. 급수시스템의 경우에는 파열 및 누수발생과 관련되어 사용되는 비용은 분실되는 물의 직적비용, 급수시스템 수리에 따른 공사비용, 공급중지와 관련된 사회적 비용이 있다. 파열 및 누수를 신속하게 감지하는 것은 물 손실에 의해 발생하는 직접 및 간접비용을 줄일 수 있다. 그러나 국내의 경우 정기적으로 매년 1회 시행되는 상수관로에 대한 누수탐지작업으로 신속한 감지 및 즉각적인 대처를 할 수 없는 실정이다. 본 연구에서는 수도관에서 발생되는 파열 및 누수를 탐지하기 위하여 블록 유입부에 설치된 유량계의 샘플링 간격의 영향에 대한 연구를 실시하였다. 적응칼만필터 알고리즘을 이용한 가변 샘플링 간격은 최대 최소 샘플링 간격과 정규화된 잔차의 상한값과 하한값 도입하여 제시하였다. 샘플링 간격의 효과를 강조하기 위해 사인 곡선, 사다리꼴 파열, 불규칙 잡음으로 구성된 가상의 유량 데이터로 알고리즘에 대한 검증실험을 진행하였고 실험 결과 샘플링 간격이 길수록 긴 시간 동안 누수 및 파열에 대한 작은 잔차를 발생시켰다. 모의실험결과 샘플링 주기를 변경함으로써 분석에 필요한 유량 데이터의 샘플수를 크게 줄일 수 있었다.

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소성 불안정 해석에 기초한 마모 손상된 전열관의 파열압력 해석

  • 신규인;박재학
    • Proceedings of the Korean Institute of Industrial Safety Conference
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    • pp.40-45
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    • 2002
  • 일반적으로 마모 손상된 원자력 발전소의 증기발생기의 전열관은 소성변형의 불안정에 의하여 파열이 발생된다. 이에 본 연구예서는 증기발생기 전열관에 평면형(flat type), 원주형(circumferential type)의 마모가 존재한다고 가정하고 소성 불안정(plastic instability) 해석에 기초하여 파열압력을 구하였다 또한 실험 결과와 비교하여 본 연구 해석 결과와 잘 일치함을 보였다.(중략)

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Experimental Analysis of Bursting Performance according to Rupture Disc Shape of Dual Pulse Motor (이중펄스모타 파열판 형상 변화에 따른 파열 영향의 실험적 분석)

  • Kwon, Tae-Ha;Cho, Won-Man;Rho, Tae-Ho;Chang, Hong-Been;Koo, Song-Hoe
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • pp.666-669
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    • 2011
  • The rupture disc shapes of bulkhead type pulse separation device(PSD) are designed for new dual pulse rocket motor. Before final design PSD, that three different rupture disc are tested and confirmed the performance of the discs. Through analyzing the test results the PSD decides, two rupture disc shapes with flow holes of eight circles and eight trapezoids.

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Extraction and analysis of rotator cuff tear area Using Clustering Based Quantization (클러스터링 기법 기반 양자화를 이용한 회전근개 건 파열 영역 추출 및 분석)

  • Park, Ji-Hun;Choi, Cheol-Ho;Song, Yu-Seon;Kim, Kwang Beak
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • pp.494-496
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    • 2017
  • 본 논문에서는 기존의 회전근개 건 파열 추출 방법을 개선하기 위하여 초음파 영상에서 환자 정보를 제거하여 ROI 영역을 추출한다. 추출된 ROI 영역에서 명암 대비를 강조하기 위해 기존의 사다리꼴 형태의 퍼지 스트레칭 기법에서 소속 함수를 개선한 퍼지 스트레칭 기법을 적용하여 힘줄과 연골 영역을 효과적으로 강조한다. 강조된 ROI 영역에서 Max-Min 이진화와 8방향 윤곽선 추적 기법 및 Monoton Cubic Spline 기법을 적용한 후에 라벨링 기법을 적용하여 힘줄 및 연골 영역을 추출한다. 추출된 힘줄과 연골 영역을 이용하여 회전근개 영역을 추출한다. 추출한 회전근개 영역에 SOM 기반 양자화 기법을 적용하여 회전근개 건 파열 영역을 추출한다. 제안된 회전근개 건 파열 영역 추출 방법을 다양한 초음파 회전근개 건 파열 영상을 대상으로 실험한 결과, 제안된 회전근개 건 파열 영역이 기존의 추출 방법보다 TPR 값이 증가되어 회전근개 건 파열 분석에 효과적인 것을 확인할 수 있었다.

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A Study on the Vented Gas Explosion Characteristics of Indoor Leakage of the LPG (실내 LPG 누출시 폭발특성에 관한 연구)

  • Oh Kyu-hyung;Kim Hong;Kim Sang-sub;Jo Yoong-do;Jo Jee-whan;Oh Shin-kyu
    • Journal of the Korean Institute of Gas
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    • v.3 no.3
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    • pp.51-57
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    • 1999
  • A study on the vented gas explosion characteristics were carried out with the liquified petroleum gas(LPG) which is used in domestics and industries fuel. To evaluate a damage by gas explosion and to predict a explosion hazards, a series of experiment have been performed in the regular hexahedron vessel of 270${\iota}$. A side of the vessel was made to setting a polyester diaphragm which was ruptured by explosion to simulate an accidental explosion which ruptured the window by explosion. Experimental parameters were LPG concentration, ignition position, venting area, a strength of diaphragm which was ruptured and distances from venting, Experimental results showed that vented gas explosion pressure was more affected by the diaphragm strength than the gas concentration, and the vented gas explosion pressure and blast wave pressure was increased with decreasing the venting area and increasing the strength of diaphragm. In this research we can find that a damage by vented explosion at the outside can be larger than the inside by blast wave pressure near the venting.

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Optimal Design of the Safety Valve by Response Surface Method (반응표면법을 이용한 안전밸브의 최적화)

  • Lee, Sang-Woo;Shin, Dae-Young;Byun, Cheol-Woong
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.5
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    • pp.551-556
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    • 2007
  • High pressure storage of the agent gas in fire suppression system was composed of tank, main valve and safety valve, which prevents the fracture of the high pressure storage. The safety valve has circular thin plate as fracture plate that was destroyed over fracture pressure. When inner pressure of the storage is reached the fracture pressure, the safety valve discharges gas and degrades simultaneously the inner pressure of the storage. There are design variables such as flow path diameter, inner diameter of the plastic packing ring, thickness of plate and fillet radius. In this variables, thickness of plate is set to be a value of 0.2mm. The main effect of variables on the inner pressure, has been decided using factorial design and statistical analysis. Therefore, the relation of variables are expressed by regression equation. It is disclosed results that the difference of fracture pressures between the equation and experiment has $2{\sim}5%$. Finally, using response surface method, the optimal design of the safety valve could be decided with safety pressure of 25MPa, where the fracture occurs on circular thin plate.