• Proceedings of the Korean Fiber Society Conference
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• 1992.06a
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• pp.68-69
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• 1992

• Composites Research
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• v.14 no.2
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• pp.8-12
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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. It is well established and versatile method for storage tanks and pipes for the chemical and other industries. In this study, tensile strength of a filament wound ring specimens were evaluated by a split disk test fixture and a dress disk test fixture. The results obtained from experiments were compared with the theoretical values from the rule of mixtures. 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 those tested by the split disk test because of higher stress concentration in edges of a split 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 for Nondestructive Testing
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• v.23 no.5
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• pp.439-444
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• 2003

Acoustic emission(AE) ran be very effectively applied to locate the damaged area in large structures by detecting the elastic waves generated during the damage process within solids. Source location in the composite structures has been, however, extremely difficult due to the acoustic anisotropy with the velocity dependence on fiber orientations. In this study, it has been shown that a newly proposed method for 2-D source location of anisotropic structures is practically applicable to the real structure. The method employes wave velocities obtained with different velocities from $0^{\circ}\;to\;90^{\circ}$ for a filament wound composite pressure vessel under the air-filled and the water-filled conditions.

• Composites Research
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• v.24 no.4
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• pp.17-22
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• 2011

In this paper, as a basic research to apply the composite sandwich to underwater vehicle, the manufacturing, analysis and test methods, and weight saving effect of a composite sandwich cylinder under external pressure were studied. A two-step manufacturing method to prevent the wrinkling of the sandwich cylinder face was proposed and the three cylinders were made and tested. Finite element results based on the shell and solid model using MSC.Nastran were compared with test results. The comparison showed that the linear finite element analysis using the shell and solid elements can predict the buckling pressure of the sandwich cylinder with approximately 3% difference. The parametric study of the filament wound cylinders revealed that the composite sandwich can reduce the weight of the cylinder more than 30% compared with the filament wound cylinder supporting the same pressure.

• Composites Research
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• v.21 no.6
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• pp.23-30
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• 2008

In this paper, the effect of the natural aging on the strength distribution and structural service life of a Filament Wound (FW) composite pressure vessel was studied. The fiber failure strain, which is varied significantly, was considered as the design random variable and the strength analysis was carried out by probabilistic numerical approach. The progressive failure analysis technique and the First Order Reliability Method (FORM) were embedded in this numerical model. As the calculation results, the probability of failure was obtained for each aging time steps and it is found that the strength degradation in FW composite pressure vessel, due to the natural aging, appears within 10 year-aging-time. As an example of the life prediction under natural aging using arbitrary laminated model, the service lifetime of 13 years was predicted based on the probability of failure of 2.5% and the design pressure of 3,250 psi.

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.73-78
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• 2011

The purpose of this study was to investigate the natural frequency of filament-wound composite towers for large scale wind-turbines using the finite element method (FEM). To define the material properties, we used both the effective property method and the stacking properties method. The effective properties method assumes that a composite consists of one ply. The stacking properties method assumes that a composite consists of several stacked plies. First, a modal analysis of the tower, filament-wound with angles of $[{\pm}30]$, was carried out using the two methods for composite material properties, the stacking method and effective method. Then, an FE analysis was performed for composite towers using filament winding angles of $[{\pm}30]$, $[{\pm}45]$, and $[{\pm}60]$. The FE analysis results using the stacking properties of the composite were in good agreement with the results from the effective properties method. The difference between the FEM and material properties methods was approximately 0~0.6%

• Journal of Ocean Engineering and Technology
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• v.25 no.2
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• pp.79-84
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• 2011

The purpose of this study was to investigate the buckling load of filament-wound composite towers for large scale wind-turbines using the finite element method (FEM). To define the material properties, we used both the effective property method and stacking properties method. The effective properties method assumes that a composite consists of one ply. The stacking properties method assumes that a composite consists of several stacked plies. First, a linear buckling analysis of the tower, filament-wound with angles of $[{\pm}60]$, was carried out using the two methods for composite material properties: the stacking method and effective method. An FE analysis was also performed for the composite towers using the filament winding angles of $[{\pm}30]$, $[{\pm}45]$, and $[{\pm}60]$. The FE analysis results using the stacking properties of the composite were in good agreement with the results from the effective properties method. The difference between the FEM results and material properties method was approximately 0~2.3%. Above the angle of $[{\pm}60]$, there was little change in the buckling load.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.2
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• pp.190-196
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• 2018

Carbon fiber/epoxy composites are typical brittle materials and have low impact properties. Recently, it is important to investigate impact characteristics of carbon fiber composites because of increasing use as automobile parts and high pressure hydrogen vessels of fuel cell electric vehicles for light weight. In this study, the low velocity impact properties of carbon fiber/epoxy composites fabricated by a filament winding method are studied. The low velocity impact properties were measured by performing tests according to ASTM D7136. The low velocity impact simulations were carried out using commercial structural analysis software, Abaqus. The absorbed energy and the delamination shapes were compared between the experimental and simulation results. The numerical analysis method showed that the absorbed energy decreased with the reduced number of cohesive elements in the composite models.

• Journal of Aerospace System Engineering
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• v.17 no.6
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• pp.127-132
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• 2023

In this study, designing of a Type 4 pressure vessel using the filament winding method was conducted. In order to prevent leakage in consideration of the design of the hydrogen storage tank, a liner was designed by applying high-density polyethylene (HDPE), and the composite structure was designed by stacking carbon/epoxy in the hoop and helical directions. As a theoretical approach, the angle of the helical fiber and fiber thickness of each hoop and helix were designed. The safety of the design was verified using the commercial software ANSYS.

• Textile Coloration and Finishing
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• v.9 no.1
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• pp.50-60
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• 1997

최근섬유산업의 어려움은 국내 섬유산업이 시작된 이래 최대의 위기상황이라고까지 불리어지고 있다. 그러나 전자, 반도체산업의 불황국면의 예견은 전체 국가적인 차원에서 본다면 섬유산업의 재건을 꾀할 기회가 아닌가 보여진다. 이러한 상황에서 부가가치가 높은 제품개발만이 한국 섬유산업이 살아갈수 있는 방향이라는 것은 누구도 부인할 수 없는 현실이다. 최근 絲 생산업체에서는 모두 복합사의 생산에 모든 정보를 얻으려는 노력을 기울이고 있으며 기술개발에 노력을 경주하고 있다. 絲加工 공정을 포함한 제직준비 공정에서 부가가치가 높은 복합사 생산기술은 여러가지 방법이 있다. 본고에서는 인터레이스 노즐 종류별 絲 제품 개발 방향 및 Taslan 노즐과 이들 인터레이스 노즐을 이용한 특수 絲 개발 가능성 그리고 기타 여러가지 제직 준비시설을 이용한 특수 복합사 제조기술을 서술함으로써 중소기업 위주로 구성된 복합사 제조기업에 기초 기술자료를 제공하고자 한다.