• 한국추진공학회지
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• 제3권2호
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• pp.56-65
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• 1999

본 연구에서는 와인딩시 공정조건의 변화가 필라멘트와인딩 복합재의 기계적 특성에 미치는 영향을 조사하였다. 와인딩시의 공정변수로는 섬유장력과 섬유엔드수를 고려하였다. 고려한 시편은 필라멘트와인딩 공법으로 제작된 링 시편으로 강화섬유는 TZ-507 탄소섬유와 IZ-40 탄소섬유를 사용하고 수지는 필라멘트와인딩용 에폭시를 사용하였다. 와인딩시 섬유장력은 0.5kgf에서 3.0kgf의 범위에서 변화시켰으며 섬유엔드수는 1엔드에서 6엔드의 범위에 서 변화시켰다. 와인딩시 섬유장력과 섬유엔드수를 변화시킨 링 시편의 섬유체적비와 기공함유율은 황산용해법을 적용하여 측정하였으며 이들 링 시편의 기계적 특성은 스프릿 디스크 시험을 통해 평가하였다. 본 연구의 수행을 통해 얻어진 결과들로 판단하면 와인딩시 섬유 장력과 섬유엔드수는 필라멘트와인딩 복합재의 섬유체적비와 기공함유율을 변화시킬 뿐 아니라 필라멘트 와인딩 복합재의 기계적 특성에도 밀접한 영향을 미친다. 따라서 필라멘트와인딩 복합재의 구조성능을 극대화하고 생산성을 향상시키기 위해서는 최적의 필라멘트 와인딩 공정조건이 적용되어야 한다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 추계학술발표대회 논문집
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• pp.203-207
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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 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. 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 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.

• Fibers and Polymers
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• 제7권3호
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• pp.317-322
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• 2006

Reduction of yam hairiness by nozzles in ring spinning and winding is a new approach. Simulation of the airflow pattern inside the nozzles provides useful information about actual mechanism of hairiness reduction. The swirling air current inside the nozzles is capable of wrapping the protruding hairs around the yam body, thereby reducing yam hairiness. Since production rate of winding is very high and the process itself increases yarn hairiness any method to reduce the hairiness of yarns at this stage is a novel approach. A CFD (computational fluid dynamics) model has been developed to simulate the airflow pattern inside the nozzles using Fluent 6.1 software. In this study, both S- and Z-type nozzles having an axial angle of 500 and diameter of 2.2 mm were used for simulation studies. To create a swirling effect, four air holes of 0.4 mm diameter are made tangential to the inner walls of the nozzles. S- and Z-twisted yams of 30 tex were spun with and without nozzles and were tested for hairiness, tensile and evenness properties. The total number of hairs equal to or exceeding 3 mm (i.e. the S3 values) for yam spun with nozzle is nearly 49-51 % less than that of ring yams in case of nozzle-ring spinning, and 15 % less in case of nozzle-winding, while both the yarn types show little difference in evenness and tensile properties. Upward airflow gives best results in terms of hairiness reduction for nozzle-ring and nozzle wound yams compared to ring yarns. Yarn passing through the centre of the nozzle shows maximum reduction in S3 values.

• 한국정밀공학회지
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• 제30권7호
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• pp.741-748
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• 2013

A conventional packing ring was designed with a large clearance to prevent damage due to the vibration of the rotor, which can lead to an increase in steam leakage. In this study, a flexible packing ring using winding springs was developed to prevent damage to the rotor teeth by minimizing vibration, while maintaining a smaller clearance than that of conventional rotor designs. Theoretical analysis and finite element analysis (FEA) were used to design the winding spring to satisfy the specified allowable stress limit and minimum load requirements. The shape of the winding spring was designed by applying curves to the center and end parts of a flat spring. Computational fluid dynamics (CFD) analysis was used to predict the leakage of the flexible packing ring. Flow rate measurement tests were performed to verify the leakage reduction efficiency and the reliability of the CFD analysis.

• Journal of Advanced Marine Engineering and Technology
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• 제25권1호
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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.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2000년도 추계학술대회 논문집(Proceeding of the KOSME 2000 Autumn Annual Meeting)
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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.

• Composites Research
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• 제14권2호
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• pp.8-12
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• 2001

필라멘트 와인딩 공법(filament winding process)은 회전하는 맨드렐에 로빙(roving)형태의 연속섬유를 감는 비교적 간단한 공정이다. 이것은 저장탱크, 화학용 파이프, 그리고 다른 산업에 사용되는 안정적이고 다양한 공법이다. 본 연구에서는 split disk test 치구와 dress disk test 치구에 의한 필라멘트 와인딩 링 시편의 인장강도 값을 실험에서 얻어진 결과와 혼합법칙에 의해 얻어진 이론적인 값을 비교하였다. 이 논문의 목적은 필라멘트 와인딩 구조물의 인장 특성 평가에 대한 적합한 시험법을 제안하고 있는 것이다. dress disk test 치구로 시험한 링 시험편의 인장강도는 split disk test 치구의 모서리 부분에서 발생하는 응력집중 때문에 split disk test의 시험 결과보다 이론적인 인장강도 간에 잘 근절함을 보여준다. 이 실험 결과 시험 치구의 기하학적 형상과 섬유의 연속성, 섬유 장력 그리고 시험편의 응력 집중에 영향은 받음을 알 수 있었다.

• 한국산학기술학회논문지
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• 제21권7호
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• pp.577-582
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• 2020

발전소에서 생산된 전기는 여러 단계의 변전과정을 거쳐 소비자에게 전달된다. 이 때 각 소비자에게 적합한 전압으로 송전하기 위해 초기 송전단계 및 산업단지 및 공장과 같은 고전압이 필요한 경우에 사용되는 초고압변압기는 권선 단부에서 고압의 불평등 전계가 형성되어 절연파괴의 위험을 내재하고 있다. 초고압변압기는 전압의 승압과 강압을 위해 권선, 철심이 가장 중요한 부품이다. 특히 권선의 경우 전압이 직접 인가되면서 전압의 크기를 변환하는데 핵심적인 역할을 한다. 이때 권선 단부는 그 형상에 의해 불평등 전계가 형성되고 특히 권선의 모서리에 높은 전계 스트레스가 발생한다. 이러한 불평등 전계에 의한 권선 단부의 전기적 응력을 분산하기 위하여 정전링을 사용하는데 이 정전링은 권선 상·하단 단부에 설치된다. 이러한 정전링을 설계하기 위해서는 다양한 변수를 고려하여야 하지만 그 중 정전링 곡률, 정전링 표면의 절연지 두께, 권선과 권선사이에 설치되는 배리어 수, 배리어 두께가 정전링에 발생되는 전계 스트레스에 어떠한 영향을 미치는지 유한요소법(Finite Element Method)을 통해 확인하였고 그 결과를 통해 정전링 설계 시 고려해야 할 사항을 제안하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제22권2호
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• pp.139-145
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• 1998

Filament winding method is widely used for composite fabrications using low viscosity liquid for-mation and processing asymmetrical structures of pressure vessel pipe rocket motor case etc. The filament winding method is affected by several parameters such as pot life of process time viscosi-ty of resin filament winding temperature and schedules curing condition and post curing condi-tion of resin. To develope high functional composite materials the rotation(5, 15, 20, 30rpm) of the winding machine was controlled by D.C motor. And the wiper to give proper tension was equipped between strand and resin bath. The resin is hooked by the design wiper. The adequate cure schedule was found by DSC. NOL ring test is carried out to investigate the basic physical properties such as design technology. The void contents in filament winding is generally higher than that of the prepreg laminated plate. These high contents of void can make a crack in resin in spite of low deformation. These problem was solved by giving tension in processing. To improve the characteristics of fiber volume fraction void contents resin/fiber bonding the winding speedc is changed under constant tension. It was found that resin impregnation was not different from in fiber contents void contents at the range of 0.5~1kg tension but it was found that resin was not impregnated at the above of 1.5kg tension. In burst test a pure PE liner was failed at a nozzle part under the $14kg/\textrm{cm}^2$ pressure but a pressure vessel of CNG was failed at a cylinder part under the $200kg/\textrm{cm}^2$ pressure.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1973년도 산학협동세미나 및 학술발표회 초록
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• pp.124-126
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• 1973