• 한국정밀공학회지
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• 제20권11호
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• pp.150-157
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• 2003

In this paper, the large deformation of hollow silicon rubber gasket is treated. The frictional contact occurs between groove and the outer part of hollow gasket, and the frictional self-contact exists in the inner parts of hollow gasket. The silicon rubber has the nonlinear elastic behavior and its material property is approximately incompressible. Hence, the stress analysis requires an existence of a strain energy function, which is usually defined in terms of invariants or stretch ratio such as generalized Mooney-Rivlin and Ogden model. Considering large compressive deformation and friction, Mooney-Rivlin 3rd model and Coulomb's friction model are assumed. The numerical analysis is obtained by the commercial finite element program MARC. But, due to large deformation, the elements degenerate in the inner parts of hollow gasket. This means that the analysis of subsequent increments is carried out with a very poor mesh. In order to continue the analysis with a sufficient accuracy, it is necessary to use new finite element modeling by remesh. Experiments are also performed to show the validity of present method. As a conclusion, numerical results by this research have good agreements with experiments.

• 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.

• 설비공학논문집
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• 제22권6호
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• pp.413-418
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• 2010

The amount of heat loss of a refrigerator through the gasket is nearly 30% of total refrigerator heat loss. In this paper, quantitative evaluation for the effects of various effort to reduce heat losses through the gasket. The first trial is to extend the inner gasket to prevent the heat loss flowing from the inner of refrigerator. The effects of thermal conductivity changes of gasket and magnet are investigated by the numerical heat transfer analysis. The position change of hot line is also examined in the present research. From the present result of the numerical simulation of heat transfer, we are able to reduce the heat loss about 20~40% by using inner gasket extension. The reducing of thermal conductivity of gasket is considerable in the heat loss reduction. On the other hand, the thermal conductivity change of magnet has no apparent effect in heat loss reduction. The position change of hot line has considerable positive effect in the reduction of heat loss near gasket region.

• 설비공학논문집
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• 제26권3호
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• pp.137-143
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• 2014

A gasket is known as an important component for mechanical sealing between mating surfaces. In case of the refrigerator, a gasket is generally installed into the edge line of a door to prevent cold air leaking out from the inside of a cabinet. The gasket shape used in a refrigerator is very complicated; it has a few deformable small rooms and wings (upper part) and inserting part (lower part) into the door. By the intricate shape, it takes much time and trouble on analysis by using a full-shape model. To settle down this problem, an effective design way of a gasket is proposed in this work. The inserting part is parametrically designed using FEM without considering the complicate upper part, Through this work, computational time and efforts are much reduced comparing to the full-shape analysis method. And the performance of a newly designed gasket was evaluated qualitatively.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집A
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• pp.321-325
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• 2000

Gasket of vehicle engine maintains airtight between cylinder head and engine block under high temperature and pressure, and plays important role in heat conduction of engine. And the characterization of the nonlinear behavior of metal gasket fer various bead shapes is very important as basic research for estimation of gasket durability. But it is very difficult to analyze the behavior of gasket In real experiment. In this paper, to analysis effects of the bead shape on the nonlinear behavior of cylinder head gasket under uniform pressure, the virtual experiment using the nonlinear finite element method was performed. Results are analyzed with residual deformation and the sealing pressure. With the increase of the height and the width of bead, the residual deformation and the sealing pressure increase. And if the height is very high and the width is very narrow, the wrinkles are occurred in the gasket while working.

• 설비공학논문집
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• 제21권5호
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• pp.305-310
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• 2009

The amount of heat loss of a refrigerator through the gasket is nearly 30% of total refrigerator heat loss. In this paper, quantitative evaluation analysis of heat loss through gasket is established with numerical heat transfer analysis. Extending the gasket shape to protect the heat loss from the gasket, power consumption is measured by using real refrigerator in a temperature and humidity chamber and suggest the gasket shape to reduce the heat loss. From the present result of the numerical simulation of heat transfer and experiment with varying gasket shape, we are able to reduce the heat loss about 20-40% by using extended gasket and the power consumption can be reduced about 5%.

• 한국기계가공학회지
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• 제20권10호
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• pp.95-101
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• 2021

An analysis was conducted to predict the behavior of gasket by applying an optimal-strain energy-density function selected through a uniaxial tensile test and an analysis of the gasket used in an actual hydrogen fuel cell. Among the models compared to predict the materials' properties, the Mooney-Rivlin secondary model showed the behavior most similar to the test results. The maximum stress of the gasket was not significantly different, depending on the location. The maximum surface pressure of the gasket was higher at positions "T" and "Y" than at other positions, owing to the branch-shape effect. In the future, a jig that can measure the surface pressure will be manufactured and a comparative verification study will be conducted between the test results and the analysis results.

• 한국기계가공학회지
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• 제21권1호
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• pp.66-72
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• 2022

The Mooney-Rivlin second order optimal strain energy function derived through uniaxial tensile test and analysis was applied to a gasket to confirm the internal stress and surface pressure generated during compression. The Taguchi method, a statistical technique, was used to design the optimum shape of the gasket, and through characteristic evaluation, the optimum shape of the gasket was obtained when the reference plane (T: 0.15 mm), contact surface (W: 1.00 mm), and curvature (R: 0.30 mm) were used. It was determined that the optimum shape yields a von Mises stress of 4.83 MPa, and the contact pressure stress is 20.14 MPa, which satisfies breakage and sealing requirements. In the future, we plan to manufacture a jig that can measure surface pressure to conduct comparative verification studies between the test results and analysis results.

• 대한기계학회논문집B
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• 제36권4호
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• pp.457-463
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• 2012

최근 사용자의 편의성과 냉장고 저장 공간의 확보를 위해 냉장고 문과 내벽을 얇게 제작하고 있다. 따라서 냉기차단 벽두께의 감소로 인하여 내 외부 온도차가 일정수준 이상으로 발생하고 이에 따라 표면의 이슬 맺힘 현상이 문제가 되는데, 이는 냉장고 설계에 있어 해결되어야 할 중요한 문제이다. 문제를 해결하기 위해 지금은 일반적으로 전기히터와 같은 발열체를 사용하였는데, 이 경우에 불필요한 전력소모가 뒤따른다. 본 연구에서는 기존방식과 달리 전기를 사용하지 않고 기계적 구조변경을 통한 해결방안으로 가스켓 최적화와 냉동냉장실 내벽두께 조정을 통해 표면에 이슬 맺힘 현상을 저감하는 방법을 제안한다. 해석결과를 살펴보면, 히터의 사용 없이 이슬 맺힘이 발생하는 부분에서의 온도가 국부적으로 $0.39{\sim}3.07^{\circ}C$까지 상승하는 효과를 얻어서 이슬 맺힘 현상을 저감시켰다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제27회 추계학술대회논문집
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• pp.139-145
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• 2006

액체추진제로켓엔진(LRE)은 로켓의 궤도 및 동특성 제어에 있어서 가장 중용한 부분 중 하나이다. LRE 제어 목적은 주어진 추력 궤도에 맞추어 추력을 조절하는 것과 주연소실과 가스발생기 내의 연소가스의 온도가 일정 범위를 넘어가지 않도록 추진제의 혼합비를 일정하게 유지시키는 것이다. 이런 제어 목적을 가진 LRE는 LRE를 구성하고 있는 구성품 간의 상호간섭에 의하여 다중제어가 쉽게 이루어지지 않는다. 본 연구에서는 LRE에 대한 동특성 모델을 구성하였으며 PID 제어와 PID+Q-ILC 제어로직을 적용한 결과에 대해 해석하였다. 전산모사 결과, PID 제어 보다 PID+Q-ILC 제어 방식을 적용할 경우 오차를 더욱 더 줄일 수 있는 것을 확인하였다.