• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.378-379
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• 2008

Recently, composite hollow bushings have been increasingly employed mainly from the various characteristics. Composite bushings are superior to porcelain bushings in several respects, including lighter weight, better anti-pollution and anti-explosion properties, and easer manufacturing. Filament wound GRP tubes which have various winding angle were manufactured by using a filament winding machine. This paper will show some design issues and winding condition for composite bushing. And, results show that the winding condition of composite GRP tubes can be used to improved their bending strength and pressure, For bending and pressure tested, tubes with the hybrid winding pattern show higher strength than those of unit winding pattern. Also, the influence of absorption was evaluated through such as measurement of the dye penetration test and water diffusion test, also aspects of surface state using scanning electron microscopy.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.303-309
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• 2015

In this study, a vehicle dynamic analysis and roller rig test were performed to evaluate the applicability of a suspensionless composite bogie to railway vehicles. A vehicle dynamic analysis was carried out under different rubber bushing stiffness values. The stiffness of the rubber bushing that plays a role in guiding wheel sets was varied in the range of 10-100 MN/m, in 10-MN/m steps. Based on the results, the composite bogie with a rubber bushing stiffness of more than 40 MN/m satisfied the design requirements. In addition, a rubber bushing with a stiffness of 81 MN/m was fabricated, and a roller rig test was performed. Based on the test results, the vehicle equipped with the composite bogie had a critical speed of 363 km/h, which agreed with the simulation result within an error of 10%.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.10a
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• pp.163-166
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• 2003

Since the track pin is subjected to large transverse track tension from the track link, conventional track pins for high mobility vehicles are usually made of high strength steel, which increases the weight of tracked vehicles due to the high density of steel. In this paper, several composite materials were employed for track pin design to reduce weight of track pin as well as to enhance the fatigue life of rubber bushings. Especially the effects of shear stiffness of the composites on the life of rubber bushing were investigated.

• Proceedings of the KIEE Conference
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• 2000.11c
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• pp.547-549
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• 2000

Silicone insulators have many advantages over porcelain insulators. Especially silicone insulators have good characteristics of impact hardness, surface insulation, ease of processing, mass productivity and don't have risk of bombardment and vandalism. Recently insulation part made by silicone are becoming widely used. In this paper we introduce the development of Sealing End for 132kV XLPE cable with silicone composite hollow insulator and the adoption of it to a actual transmission line in abroad. This paper contains of design procedure, structure, electrical performance of it.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.6
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• pp.1013-1017
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• 2012

Advanced composite-sintered bushings are widely utilized in the areas of excavators and injection molding machines as a journal bearing. Since the bearings are mainly used under high loads, service life should be long and the stored oil of inner bushings has to be continually fed into the bearing. The composite-sintered bushings are consisted of the two different materials; outer steel materials and inner porous sintered materials respectively. High temperature diffusion bonding has been applied for holding the both materials of the bushing together. Therefore, it is very important that the bonding reliability has to be assured and evaluated in manufacturing process. Finite element method (FEM) is performed in order to evaluate the minimum allowable flaw sizes that are possibly generated in the composite-sintered bushings. Additionally, the composite-sintered bushings were undergone ultrasonic C-scan tests to find out the size of inherent flaws through artificially simulated UT signal analysis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.225-226
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• 2008

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1181-1186
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• 2008

Insulators which are used in the domestic electrical industries are mostly depended on importation from some advance countries. Even though insulators which are made of ceramic material have been mostly used domestically, the ratio of usage on composite insulators is recently being increased because of difficulties in manufacturing and high cost regarding ceramic stuffs. In this research, we are trying to develop the composite insulators which are very efficient in insulation regardless of the matter of weight. Even though the technique of manufacturing composite insulator are quite generalized worldwide at the moment, one of the most important issue is to keep security on the know-how that an ingredient of insulated material named 'SF6 gas' is included. Therefore, The aim of this paper is to improve the bonding force and air tight property between two components of composite insulator, Flange and FRP Tube.

• Tribology and Lubricants
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• v.22 no.1
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• pp.1-7
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• 2006

The sliding friction and wear properties of mineral fiber reinforced composite(MF) and glass fiber reinforced composites(GF) are investigated to clarify their field of use and the role of each fiber in friction material. Friction and wear test reveals that GF composite has better wear resistance even though with low friction coefficient, comparing with MF composite. Glass fiber strengthen effectively the matrix and may absorb friction energy to convert it into the fracture energy of them, as well as its lubricative role. However, mineral fiber in MF composite is too small to strengthen the matrix. Then MF composite are easily plowed and worn out by asperity on counter material. Friction coefficient of MF composite is higher friction coefficient than that of GF composite and varied widely with test.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.07a
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• pp.886-889
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• 2001

Silicone rubber is being used for the housing material of outdoor high voltage insulators such as composite insulator, bushing, surge arrestor and cable terminator because of good tracking and erosion resistance, good hydrophobicity and recovery of hydrophobicity and chemical stability. But, the leakge current occurs on surface of the composite polymeric insulation materials when the insulator is used for a long time with severe contaminative condition and it can lead the contamination flashover. So the leakage current is important to estimate the condition of the silicone rubber surface. In this paper, aging characteristics of silicone rubber used for outdoor insulation have been hydrophobicity of silicone rubber in salt fog chamber with average leakage current monitoring for observing the transformation of surface degradation properties of silicone rubber with different ATH(alumina trihydrate, A1$_2$O$_3$$.$3H$_2$O) filler contents. The experimental results show that a higher peak leakage current and to raise a long time for tracking with increasing amount of ATH by the salt fog and heat recycle ageing.

• Progress in Superconductivity
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• v.13 no.1
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• pp.24-27
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• 2011

High voltage insulation in cryogenic environment is one of big issues for development of superconducting power application, such as superconducting fault current limiter, transformer, transmission cable, and so on. We had proposed a composite solid insulator composed of plastics and polymer insulation sheets for a use of high voltage superconducting power applications. It is well known that the G10 FRP keeps its mechanical strength at very low temperature and the PPLP is very good insulator adopted as insulations for superconducting transmission cables. The composition of these two materials will show very good electrical and mechanical properties adequate for the insulation components of superconducting power applications, such as bushing, insulation barrier, and even for a cryostat. Dielectric strengths of prepared samples were measured at the temperature of boiling point of liquid nitrogen at atmospheric pressure, which will be presented in this paper to show a usefulness of this technique.