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Song, J.S.;Kang, K.Y.;Hong, S.S.;Kwon, Y.N.;Lee, J.H.;Kim, Y.H.
- Proceedings of the Korean Society for Technology of Plasticity Conference
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- 2007.05a
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- pp.332-335
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- 2007
The superplastic forming (SPF) has been widely used in the automotive and aerospace industry because it has great advantages to produce very light and strong components. Finite element method (FEM) is used to model the process of superplastic forming/diffusion bonding (SPF/DB), to predict the pressure-time curve and to analyze the process parameter. In this study, process design of SPF/DB is carried out a 3-sheet sandwich part. SPF/DB process with pressure control was analyzed by using finite element method. For obtaining proper shape, step-by-step pressurization is proposed. The first step of SPD/DB process is obtained by applying of pressure in patches. From the next step it applied pressure to all regions (between inner sheets, between inner and face sheets). By using the proposed pressurization scheme, deficit in part shape is found to be eliminated.
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Park, Yong-Hwan
- Proceedings of the Korea Institute of Fire Science and Engineering Conference
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- 2005.05a
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- pp.47-55
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- 2005
Fire extinguisher, which is cost effective and easily accessible, is a very effective way of fire suppression. To keep its initial performance it needs periodical inspection and appropriate maintenance. However, many fire extinguishers of which the powder is incompletely coated deteriorates due to the moisture and leak of charge pressure after several years. Accordingly inappropriate powder replacement and pressurization has widely been doing by unqualified persons. Also, the absence of lifetime for fire extinguisher made people keep old bad fire extinguisher without precise inspection. This study specified those issues through case studies and suggested some ways for the systematic improvement.
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Hwang, Seong Sik;Kim, Hong Pyo;Kim, Joung Soo
- Corrosion Science and Technology
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- v.3 no.1
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- pp.30-33
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- 2004
It has been reported that some events of a rupture of seam generator tube have occurred in nuclear power plants around the world. Main causes of the leakage are from various types of corrosion in the steam generator(SG) tubings. Primary water stress corrosion cracking(PWSCC) of steam generator tubings have occurred in many tubes in Korean plant, and they were repaired using sleeves or plugs, In order to develop proper repair criteria, it is necessary to ascertain the leak behavior of the tubings. A high pressure leak and burst testing system was manufactured. Various types of Electro Discharged Machined (EDM) notches were developed on the SG tubes. Leak rate and burst pressure were measured on the tubes at room temperature. Burst pressure of the part through wall defected tubes depends on the defect depth, Water flow rates after the burst were independent of the t1aw types; tubes having 20 to 60 mm long EDM notches showed similar flow rates regardless of the defect depth. A fast pressurization rate gave the tube a lower burst pressure than the case of a slow pressurization.
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Sin, Jae-Myung;Han, Dong-Seop;Han, Geun-Jo
- Proceedings of the Korean Institute of Navigation and Port Research Conference
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- 2010.04a
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- pp.407-409
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- 2010
The brake system is very important part of the machine operating system of machine. If the machine does not stop during operation, accidents and facility damage, loss of life can cause. This ship is also in the same. In this study, After we had to change the original shape for the braking force improvement of the Mooring winch brake system, we analyzed the braking force and structural stress analysis of the changed Mooring Winch.
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