• Journal of Advanced Marine Engineering and Technology
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• v.25 no.1
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• pp.87-94
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• 2001

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And now it is well established as a versatile method for storage tanks and pipe for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture. The results obtained from experiments were compared with the theoretical values obtained by the rule of mixture. And the purpose of this paper is to suggest an appropriate test method for the evaluation of tensile properties of filament wound structures. The tensile strength of a ring specimens tested by the dress disk test showed better agreement with the theoretical values than of a ring specimen tested by the split disk test because the stress concentration in edges of s split disk test fixture is more severe than the that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.58 no.2
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• pp.136-141
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• 2009

An AC generator is an important components in producing a electric power and so it requires highly reliable protection relays to minimize the possibility of demage occurring under fault conditions. Conventionally, a DFT based RDR has been used for protecting the generator stator winding. However, when DFTs based on Fourier analysis are used, it has been pointed out that defects can occur during the process of transforming a time domain signal into a frequency domain one which can lead to loss of time domain information. This paper proposes the internal fault detection and fault type discrimination for the stator winding by applying the detailed coefficients by Daubechies Wavelet Transform to overcome the defects in the DFT process. For the case studies reported in the paper, a model system was established for the simulations utilizing the ATP, and this verified the effectiveness of the proposed technique through various off-line tests carried out on the collected data. The propose method is shown to be able to rapidly identify internal fault and did not operate a miss-operation for all the external fault tested.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2000.11a
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• pp.15-20
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• 2000

Filament winding process is a comparatively simple operation in which continuous reinforcements in the form of roving are wound over a rotating mandrel. And it is now well established as a versatile method for storage tanks and pipe for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by split disk test fixture and dress disk test fixture. The results obtained from experiments were compared with the theoretical values obtained by the rule of mixtures in composites . And the purpose of this paper is the suggestion of an appropriate test method for the evaluation of tensile properties of filament wound structures. The tensile strength of a ring specimen tested by the dress disk test showed better agreement with the theoretical values than that of a ring specimen tested by the split disk test because the stress concentration in edges of a split disk test fixture is more severe than that of dress disk test fixture. The results showed that the tensile strength of a ring specimen was influenced by the geometry of test fixture, the continuity of fibers, fiber-tension, fiber-end and stress concentration in specimen.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.4
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• pp.97-103
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• 2017

The objective of this study is to develop and commercialize an on-board fuel storage system for CNG vehicles. A type 4 vessel is made of resin-impregnated continuous filament windings on a polyamide (PA6) liner. In particular, this study localized the PA6 liner's fabrication and development. To analyze the filament winding, a specimen test was performed, and the results were verified values obtained using finite element analysis. In this study, the filament winding and fibers were optimized for a 207 bar composite cylinder in a compressed natural gas vehicle.

• Journal of Magnetics
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• v.21 no.3
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• pp.413-420
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• 2016

The permanent magnet synchronous motor has high efficiency driving performance and high power density output characteristics compared with other motors. In addition, it has good regenerative operation characteristics during braking and deceleration driving condition. For this reason, permanent magnet synchronous motor is generally applied as a power train motor for electrical vehicle. In permanent magnet synchronous motor, the most probable causes of fault are demagnetization of rotor's permanent magnet and short of stator winding turn. Therefore, the demagnetization fault of permanent magnet and turn fault of stator winding should be detected quickly to reduce the risk of accident and to prevent the progress of breakdown of power train system. In this paper, the fault diagnosis method using high frequency low voltage injection was suggested to diagnose the demagnetization fault of rotor permanent magnet and the turn fault of stator winding. The proposed fault diagnosis method can be used to check the faults of permanent magnet synchronous motor during system check-up process at vehicle starting and idling stop mode. The feasibility and usefulness of the proposed method were verified by the finite element analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2006.04a
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• pp.3-9
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• 2006

Among many fabrication methods of composite materials, filament winding is the most effective method for fabricating axis-symmetric structures such as pressure tanks and pipes. Filament wound pressure tanks are under high internal pressure during the operation and it has the complexity in damage mechanisms and failure modes. Fiber optic sensors, especially FBG sensors can be easily embedded into the composite structures contrary to conventional electric strain gages (ESGs). In addition, many FBG sensors can be multiplexed in single optical fiber using wavelength division multiplexing (WDM) techniques. In this paper, we fabricated several filament wound pressure tanks with embedded FBG sensors and conducted some kinds of experiments such as an impact test, a bending test, and a thermal cycling test. From the experimental results, it was successfully demonstrated that FBG sensors are very appropriate to composite structures fabricated by filament winding process even though they are embedded into composites by multiplexing.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.3
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• pp.109-117
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• 1993

A carbon/epoxy composite drive shaft used for the power transmission of the automobiles with steel joints. Compared with the metallic drive shaft, the composite one has the weight saving of 50% with equivalent torsional strength and fatigue characteristics. In this study, the filament winding technique for the composite tube and composite/metal joining technique are estabilished. The performance test of the drive shaft is carried out. The optimal condition of the surface roughness of the steel adherend was $1.5{{\mu}m}$ to $2.5{{\mu}m}$, and the optimal condition of the bonding thickness was 0.15mm. Maximum torque and torsional stiffness of the composite drive shaft manufactured by filament winding process were found to be $210kg{\cdot}m$ and $18.5kg{\cdot}m/deg$, respectively.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2059-2065
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• 2008

In this paper, quasi-static crushing tests of composite circular tubes under axial compression load are conducted to investigate the energy absorption characteristics. Circular tubes used for this experiment are glass/epoxy (GFRP) composite tubes, which is fabricated by the filament winding method. One edge of the composite tube is chamfered to reduce the initial peak load and to prevent catastrophic failure during crushing process. Two suggested trigger mechanisms for the composite tubes are investigated. Crushing modes are mainly affected by thickness/diameter ratio, and average crushing loads are mainly affected by their cross-sections. Energy absorption characteristics vary significantly as a function of the tube geometry, trigger mechanism, t/D ratio and the cross-sectional shape.

• Korean Journal of Computational Design and Engineering
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• v.3 no.1
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• pp.22-30
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• 1998

The deflection yoke (DY) controls the direction of the electron beam that falls on the screen of the television monitor. Its quality depends on the shape and density of coils wound around the DY coil separator. Winding frames are used to make these coils, and therefore, their shapes are essential in making quality coils. A reverse engineering(RE) is applied to create the 3D model of the winding frame. It considerably shortens the design verification time and shows the level of accuracy that is feasible in the production mode. The paper explains each step of the reverse engineering process in detail.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.79-81
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• 2000

Outdoor insulation of overhead distribution lines with wood, concrete and steel pole has been safety under various environmental conditions including contamination, moisture condensation, rain and lightning overvoltages. In this paper introduce to FRP technology of the power distribution single pole. FRP pole has been used very much as high strength material for insulators because of its high strength and good insulation properties. In addition, FRP pole was made by filament winding method. In a filament winding process, a band of continuous resin-impregnated rovings or monofilaments is wrapped around a rotating mandrel and cured to produce axisymmetric hollow parts.