• Title/Summary/Keyword: 멤브레인변형

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Assessment of Long-Term Stability of Geosynthetic Reinforcement Materials by Reduction Factors (감소인자에 의한 토목합성보강재의 장기안정성 평가)

  • Jeon, Han-Yong;Mok, Mun-Sung;Cho, Seong-Ho;Cha, Dong-Hwan;Kim, Seong-Cheol;Ahn, Ju-Hwan
    • Journal of the Korean Geosynthetics Society
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    • v.4 no.3
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    • pp.11-19
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    • 2005
  • Long-term stability of two type geogrids were evaluated. Membrane drawn type geogrid showed the exponential type tensile property and textile type geogrid showed the rapid increase of tensile property closer toward the break point. Short term accelerated creep test was done for textile type geogrid but done for membrane drawn type geogrid at ambient temperature because of its thermal property. Creep strain for membrane drawn type geogrid was larger than the ultimate tensile strain by tensile test. Reduction factor by creep deformation of textile type geogrid was smaller than that of membrane type geogrid. From this result, it was seen that the textile type geogrid is more stable than membrane type geogrid by creep deformation.

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Durability Assessment of Geogrids by Reduction Factors (감소인자에 의한 지오그리드의 내구성 평가)

  • Jeon, Han Yong;Heo, Dai Young
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.2
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    • pp.31-38
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    • 2004
  • Long-term stability of two type geogrids were evaluated. Membrane drawn type geogrid showed the exponential type tensile property and textile type geogrid showed the rapid increase of tensile property closer toward the break point. Accelerated creep test was done for textile type geogrid but not done for membrane drawn type geogrid because of its thermal property. Creep strain for membrane drawn type geogrid was larger than the ultimate tensile strain by tensile test and reduction factor by creep deformation of textile type geogrid was smaller than that of membrane type geogrid.

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The Measurement of Real Deformation Behavior in Pilot LNG Storage Tank Membrane (Pilot LNG저장탱크 멤브레인 실 변형 거동 측정)

  • Kim Y.K.;Yoon I.S.;Oh B.T.;Rong S.H.;Yang Y.M.;Kim J.K.
    • Journal of the Korean Institute of Gas
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    • v.9 no.3 s.28
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    • pp.27-31
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    • 2005
  • The membrane to be applied inside of the LNG storage tank is provided with corrugations to absorb thermal contraction and expansion caused by LNG temperature and pressure changes. It is very important to measure their thermal strains under LNG temperature by analytical and experimental stress analysis of the membrane. We have developed a stress measurement system using strain gages and measured the strain during cooldown and storing the LNG. We also analyzed the measured data by comparison with the FEM data.

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Finite Element Analysis on the Pitch Design of Ring Knot Type Membrane Unit (링 마디식 멤브레인 유니트의 피치설계에 관한 유한요소해석)

  • Kim Chung Kyun;Lee Young-Suk;Cha Baeg-Soon;Oh Byoung-Taek;Yoon In Soo;Hong Seong Ho
    • Journal of the Korean Institute of Gas
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    • v.3 no.3 s.8
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    • pp.58-64
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    • 1999
  • This paper has been analyzed for the stress behavior problems of the ring knot membrane unit using the finite element method about the pitch design of the membrane unit, which is one of the most important parameters in manufacturing of the membrane type LNG storage tanks. The FEM results have been compared those of the existing pitch design length. The safety problem of the ring knot membrane model, which is considered in this study, does not come out any more no matter what the pitch length is used in the extra large LNG storage tanks. But in the case of the membrane for LNG tankers, it is advantageous to design the pitch short because of fatigue strength caused by repeated loadings. Looking at the deformation behaviors of the membrane corrugation, the deformation of the hight in the y direction occurs $15{\~}50\%$ more than that of the width in the z direction. It shows also that the deformation of the membrane with $-162^{\circ}C$ cryogenic temperature is not so great compared with the deformation by hydrostatic pressure.

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The Measurement of Membrane Deformation Behavior in Kogas Pilot LNG Storage Tank by the use of Mechanical/Electrical Sensor (I) (기계적/전기적 측정 센서를 이용한 Kogas Pilot LNG 저장탱크 멤브레인 변형 거동 측정(I))

  • Kim Y.K.;Hong S.H,;Oh B.T.;Yoon I.S.;Kim J.H.;Kim S.S.
    • Journal of the Korean Institute of Gas
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    • v.7 no.3 s.20
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    • pp.13-17
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    • 2003
  • A membrane unit for Liquefied Natural Gas (LNG) storage tank is a structural member which is designed specifically for preventing undesirable LNG leakage. Membrane units have to endure gas and liquid pressures by LNG and thermal stresses by the contact with cryogenic liquid of $-162^{\circ}C$. It is of importance to assure the strengths of membrane by experimental stress analysis under the temperature of LNG. In this paper, we proposed measurement system using commercial electrical strain gage and mechanical extension meter designed for this study.

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Effect of the Curved Automotive Panels for NVH Performance Improvement (NVH 성능향상을 위한 복곡 자동차 패널의 효과)

  • Yoo, Hee;Lee, Young-Woo;Choi, Byoung-Ki;Kim, Jong-Kuk;Yum, Young-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.33 no.7
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    • pp.700-705
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    • 2009
  • In order to enhance the dynamic stiffness of automotive panel, effect of bead and curved surface was investigated. Modal test was performed for principle specimens which have various kinds of beads, holes and curved surfaces. Test was also performed for conventional dash panel assembly and rear floor panel assembly and curved shaped ones. Results showed that curved shape increased the natural frequency of automotive panel more effectively than the bead. Finite element analysis was also performed and yielded good match with the test results.

Numerical Analysis on the Stress and Deformation Characteristics of LNG Membrane Storage Tank System with Corner Protection (코너프로텍션 설치에 따른 멤브레인 LNG 저장탱크 시스템의 응력 및 변형거동 특성에 관한 수치해석)

  • Kim, Chung-Kyun
    • Journal of the Korean Institute of Gas
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    • v.13 no.6
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    • pp.9-14
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    • 2009
  • In this study, the stress and deformation characteristics of corner protection in which is fabricated in an insulation area have been analyzed using a finite element method. The proposed corner protection may increase the strength and leakage safeties of conventional LNG storage system. The stress and deformation of LNG storage tank system are computed for an insulation panel box, membrane inner tank, and prestressed concrete outer tank. The FEM computed results indicate that the stress and displacement of new membrane LNG tank system with a corner protection between an inner tank and an outer tank are reduced in comparison to those of a conventional membrane LNG tank. This is explained that the strength safety of LNG membrane tank system may be increased due to a strength stiffness of a corner protection.

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Analyzing Method of Deformation of Model Ground in Plane Strain (평면변형율 상태에 있는 모형지반의 변형해석법)

  • 임종철;주인곤
    • Geotechnical Engineering
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    • v.8 no.1
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    • pp.29-40
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    • 1992
  • One of the most important things to analyze model ground test in plane strain is to observe deformation, accurately, In this paper, the analyzing method of ground deformation by using photos of points on membrane attached on transparent acryle plate of side wall of model ground box is described. First order 4-node isoparametric elements are used to calculate strains of ole cents.

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Experimental Analysis of Corbel Part Behaviour in Inground LNG Storage Tank (지하식 저장탱크 Corbel부 실험적 거동 분석)

  • Yoon I.S.;Kim J.K.;Kim Y.K.;Kim J.H.
    • Journal of the Korean Institute of Gas
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    • v.10 no.1 s.30
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    • pp.56-60
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    • 2006
  • The connection part (corbel) between bottom slab and side wall in inground LNG storage tank has hinge conditions partly fixed by using anchor bars to reduce stress concentration. The corbel deforms in both radial and vertical directions under load conditions of the LNG tank such as LNG temperature, hydraulic pressure, etc. Membrane is an important part from the viewpoint of design because the deformation of the corbel is transformed directly to the membrane and superposed with other deformations. Behavior of the corbel has been investigated through various sensors to measure temperature, load and displacement. And the test data have been compared with finite element results analysis to propose a more reasonable design of LNG storage tank.

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