• Tribology and Lubricants
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• 제20권5호
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• pp.259-265
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• 2004

The sealing performance of O-rings is affected by working conditions such as applied pressure, operation temperature, pre-compressed ratio and material properties. In this paper, a pressurized and compressed elastomeric bi-polymer O-ring in which is inserted into a rectangular groove is analyzed by non-linear MARC finite element program based on the Taguchi experimental method. O-rings with 9 different profile models are analyzed for design parameters that are related to the diameter ratio between outer diameter and inner one of bi-polymer O-ring, compressive ratio, groove angle and groove depth. The calculated FEM results showed that the affection ratio of design parameter dlD, which may control sealing pressure of O-rings, is the most influential parameter among the groove angle, groove depth and compression ratio.

• 한국자동차공학회논문집
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• 제10권3호
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• pp.143-150
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• 2002

The characteristics of rubber cup seal is highly nonlinear due to the nature of the material's non-linearity and large deformation with frictional contact. And the performance of sealing in master cylinders of automobile is one of the most important factors which affects the safety of drivers. The effects of various shape of the primary cup seal in clutch master cylinder was investigated to reduce oil leakage and to obtain a long reliable life. Deformation and distribution of stresses on the primary cup seal against hydraulic oil pressure were analyzed with changing design parameters such as depth and radius in cup-seal. The obtained results indicate that the depth of cup seal plays a major role on deformation resulting in the sealing force to the wall of clutch master cylinder.

• 한국전산유체공학회지
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• 제12권3호
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• pp.13-19
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• 2007

A numerical simulation on the heat transfer and flow field was carried out to improve the performance of the shell and tube heat exchanger. The steady incompressible 3-D Navier-Stokes solution is obtained with the actual operational condition and geometry of the heat exchanger. Based on this study, it is noted that the present geometry of the heat exchanger causes poor heat transfer since the air inside shell does not flow through the tube bundle, but around it. The enhancement of the heat transfer can be achieved by the variation of the design factor like the sealing strip located on the top/bottom and middle of the baffle, but it causes the increasement of the pressure drop. In this paper, the effects of the location and size of the sealing strips and flow rate through the heat exchanger on the heat transfer and pressure drop are studied.

• 항공우주시스템공학회지
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• 제2권4호
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• pp.25-30
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• 2008

In general, we utilize momentum wheel to control spacecraft. It needs vacuum test to analyze the effect of space environments. The conventional vacuum connector which is composed of steel has problems for test with built in momentum wheel because of weight, thermal expansion, etc. We suggest possibility to manufacture the vacuum connector using aluminum mount, epoxy and industrial D-Sub considering cost, weight. We verify the performance through vacuum test.

• 한국진공학회지
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• 제15권5호
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• pp.475-484
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• 2006

컨플래트 (Con-Flat) 및 개량형 (IPD) 플랜지에서 개스킷을 넣고 체결할 때 나사의 체결력 또는 선하중에 따라 플랜지 및 개스킷에 발생하는 변형량, 응력 분포, 접촉 면압 따위의 계산을 통해 플랜지 날의 형상이나 체결조건이 기밀에 미치는 영향을 분석 또는 예측하는 것이 가능한지를 판단해 보았다.

• 한국표면공학회지
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• 제53권5호
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• pp.249-256
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• 2020

As the size of manufacturing equipment for LCD and OLED displays increases, replacement of existing heavy stainless steel components with light metals, such as aluminum alloys, is being more important in semiconducting and display manufacturing industries. To use aluminum alloys for components in semiconducting and display industries, it is important to develop a new anodization method for improved performance of anodic oxide films than conventional anodization method based on sulfuric acid. In this work, optimum applied current density and the best sealing methods for anodic oxide films in 3% oxalic acid were explored. Experimental results showed 2.5 A/dm2 is the best applied current density for improved hardness and dielectric breakdown voltage. Sealing of the anodic oxide films further improved their hardness, dielectric breakdown voltage and resistance to HCl, by which application of anodic oxide films become applicable for components in semiconducting and display industries.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2001년도 제33회 춘계학술대회 개최
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• pp.392-400
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• 2001

The sealing performance of an elastomeric O-ring seal using bi-materials has been analyzed for the contact stress behaviors that develop between the O-ring seal and the surfaces with which it comes into contact. The leakage of an O-ring seal will occur when the pressure differential across the seal just exceeds the initial (or static) peak contact stress. The contact stress behaviors that develop in compressed O-rings, in common case of restrained geometry(grooved), are investigated using the finite element method. The analysis includes material hyperelasticity and axisymmetry. The computed FEM results show that the contact stress behaviors are related to a ratio of length between NBR and FFKM and temperature of vaccum chamber.

• 한국재료학회지
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• 제4권7호
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• pp.741-749
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• 1994

The planar solid oxide fuel cell(SOFC) contains several ceramic materials depending on its structure and has rdfractory metal parts for manifolds, shrouds and current leads. Among ceramic materials for planar SOFC, joining of lanthanum chromite separator and yttria stabilized zirconia(YSZ) electoyte in planar SOFC stack to give strong gas tight seals is necessary for satisfactory operation and high performance. Nevertheless, for planar SOFC/sub s/, how to seal the cell stack and gas manifold remains as one of the unsolved problems. Therefore, in this study. we investigated the joining of sintered lanthanum chromite and YSZ pellets using unsintered lanthanum chromite green films as sealent. Scanning electron microscopy(SEM) and energy dispersive X-ray analysis(EDX) revealed that Ca in the sealing material diffused and dissolved into YSZ and sintered lanthanum chromite, and unsintered lanthanum chromite green films reacted with YSZ to from a new phase at the interface. Also, the densification of unsintered lanthanum chromite green films was inpeded by the Ca migration.

• 대한기계학회논문집A
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• 제37권4호
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• pp.537-545
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• 2013

금속씰의 탄성복원력은 기밀성능을 결정하는 매우 중요한 요소이다. 본 연구는 장시간 운전조건에서 기밀성능을 유지할 수 있는 금속오링씰의 구조, 즉 탄성복원력이 우수한 구조를 얻기 위하여 컴플라이언트 메커니즘 위상최적화법을 도입하였다. 진화구조최적화법의 위상최적화 알고리듬이 사용되었으며, 강성 및 유연성을 동시에 고려하는 두 가지 종류의 목적함수가 사용되었다. 금속오링씰의 외형을 고려하여 원형의 최적화 설계영역이 고려되었으며 최적화 결과로 나타난 위상의 탄성복원력은 상용품의 탄성복원력과 비교되었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.97-100
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• 2007

Fuel Cell Stack performance, which is influenced by the maintenance of a constant internal environment, requires high levels of air tightness. Used for analysis, gasket for fuel cell is made of elastic rubber materials and placed over separator, and shape of deformation of a gasket affects the transformation separator and airtightness while fastening structure. Separator as made of steel sheet isn't broken under pressure but can affect gas and cool water flow by the plastic deformation process. Therefore， it is understood that assembly process is well developed in case distribution of stress and shape of deformation is shown uniformly. This study is conducted on the assumption that a fuel cell maintenance is advantageous in that conditions. In this paper, analyses of unit cell and partial model were performed and distribution of stress and shape of deformation of Gasket and separator were analyzed to evaluate the airtightness while fastening structure.