• Proceedings of the Korean Society of Disaster Information Conference
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• 2023.11a
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• pp.337-338
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• 2023

본 논문에서는 유류 오염물의 흡수 반응이 가능한 반응재료에 대하여 지중 구조 재료로서의 적용성 검토를 목적으로 배합조건에 따른 다짐시험을 실시하였다. 다짐시험 결과, 주요 반응물질이 최적함수비에 미치는 영향은 미미하였으나, 최대건조단위중량의 영향인자로 평가되었다.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2002.05a
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• pp.119-122
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• 2002

The vibration qualification test of satellite antenna is required to verify that there will be no structural damage due to the severe vibration caused by the launch of satellite. For the qualification test, reasonable test load condition needs to be introduced by dynamic analysis. The present work has been performed to provide an understanding how the qualification test load can be evaluated by the results of both normal mode and sine vibration analyses with notching technique for a composite Ka-band antenna structure.

• Composites Research
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• v.14 no.3
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• pp.10-17
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• 2001

A reseach was peformed to develop composite pressure vessels in conjunction with design, fabrication, and test. Fiber pattern and angels were decided by CADFIL software and they were [$liner/15^{\circ}/15^{\circ}/90^{\circ}/18^{\circ}/90^{\circ}/21^{\circ}/21^{\circ}/90^{\circ}$]. Fabrication of bottles were done by 5-axis filament winding machine. During fabrication fiber optic sensors were embedded to measure the strain at points when internal pressure was applied by water pump. Conventional strain gage instrumentation showed the stable test results. The test results were compared to finite element analysis results and they were close each other in strain values. One can see the successful design and fabrication of single boss composite vessels.

• Journal of Korean Society of Steel Construction
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• v.13 no.6
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• pp.631-640
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• 2001

The behavior of composite materials bridge decks for use in deteriorated bridge decks replacement are investigated experimentally in this study. As for the performance evaluation of bridge decks, experimental studies on the 5 test specimens with 1/10 scale of full size were carried out. Three specimens were fabricated from sandwich upper flange and two specimens were fabricated from laminated upper flange. The constituents of bridge decks were glass fiber performs and epoxy resin. The experimental results, i.e., the maximum strength stiffness, stiffness, and deformation capacity, were summarized. The results of the finite element analysis were compared with the experimental results for the verification of validity.

• Composites Research
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• v.16 no.2
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• pp.33-40
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• 2003

In order to overcome one of the most pronounced shortcomings of conventional laminated composites, such as the low damage tolerance due to delamination, the thermoplastic materials and 3D (three-dimensional) preforms have been utilized in the manufacture of composite materials. From the newly developed process termed as the co-braiding, hybrid yarns of the thermoplastic fibers (PEEK) and reinforcing fibers (carbon) have been fabricated. In order to further enhance the delamination suppression, through thickness fibers have been introduced by way of 3D weaving technique in the fabrication of textile preforms. The preforms have been thermoformed to make composite materials. Complete impregnation of the PEEK into the carbon fiber bundles has been confirmed. For the comparison of mechanical performance of 3D woven composites, quasi-isotropic laminates using APC-2/AS4 tapes have been fabricated. Tensile and compressive properties of both the composites have been determined. Furthermore. the open hole, impact and CAI(Compression After Impact) tests were also carried out to assess the applicability of 3D woven textile reinforced thermoplastic composites in aerospace structures.

• Polymer(Korea)
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• v.28 no.4
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• pp.285-290
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• 2004

Nondestructive damage sensitivity of carbon nanotube(CNT) and nanofiber (CNF)/epoxy composites with their adding contents was investigated using electro-micromechanical technique. Carbon black (CB) was used only for the comparison with CNT and CNF. The fracture of carbon fiber was detected by acoustic emission (AE), which was correlated to the change in electrical resistance, ΔR under double-matrix composites (DMC) test. Stress sensing on carbon nanocomposites was performed by electro-pullout test under uniform cyclic loading. At the same volume fraction, the damage sensitivity for fiber fracture, matrix deformation and stress sensing were highest for CNT/epoxy composite, whereas for CB/epoxy composite they were the lowest among three carbon nanomaterials (CNMs). Damage sensitivity was correlated with morphological observation of carbon nanocomposites. Homogeneous dispersion among CNMs could be keying parameters for better damage monitoring. In this study, damage sensing of carbon nanocomposites could be evaluated well nondestructively by the electrical resistance measurement with AE.

• Composites Research
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• v.36 no.3
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• pp.193-198
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• 2023

Currently, there are many discussions about composite materials and 3D printed composite material to weight reduction of ships. A test was conducted to confirm the applicability of the 3D printed composite material to ships and offshore structures by linking the 3D printing technology with excellent productivity and the composite material with corrosion resistance and lightweight characteristics in salt water environments. In order to apply the 3D printed composite material used in this paper to ships and offshore structures, the temperature environmental effects that can be exposed in the marine environment should be considered. Therefore, the tensile test was conducted with specimen of Carbon + Onyx, Carbon + Nylon, HSHT glass + Onyx, HSHT glass + Nylon material in low temperature (-50℃), room temperature (20℃), and high temperature (50℃) environments that can be exposed to the marine environment. As a result of the tensile test, the carbon + onyx specimen showed the highest tensile strength and the HSHT glass + onyx specimen showed the highest tensile strain. In addition, by analyzing the tested specimens, the failure mode of the 3D printed composite material specimens exposed to various temperature environments was analyzed.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.7
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• pp.1341-1350
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• 1992

This paper addresses the practical problem of finding a useful strain energy function of the incompressible rubberlike materials. It examines methods by which the form of the functions are determined and shows how the selection of experimental data influences the resulting form of the functions. From this information, an optimal choice of the form of energy functions becomes possible. Phenomenological theories used in this paper are limited to elastic, incompressible material models. Due to the nature of the phenomenological methods, these theories are accurate only for the materials treated. However, they serve as a starting basis for the study of more complicated material behaviors.

• 한국도로학회지:도로
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• v.4 no.4 s.14
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• pp.3-15
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• 2002

지금까지 1940년대부터 최근까지 건설된 미국의 시험도로에 대한 목적과 주요특징 등에 대해 알아보았다. 과거와 다르게 최근 건설된 시험도로들은 크게 도로 본선 옆에 시공한 시험도로의 형태와 시험 주로 형식의 루프구간으로 이루어져 있음을 알 수 있었다. 이는 시험주로에서는 포장재료 영향 평가를 목적으로, 시험도로에서는 포장층의 구조적 영향을 파악하기 위한 것으로 판단된다. 표 4는 최근 미국에서 건설된 시험도로를 간략하게 요약한 것이다.

• 기계와재료
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• v.22 no.4
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• pp.68-74
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• 2010

현장 운용조건하에서 사용자들이 요구하는 보증수명을 시험평가하기 위해서는 많은 시간과 비용이 소요된다. 이를 해결하기 위한 시험기술로써 흔히 가속시험이 운용되며 가속방법에는 연속적으로 사용하지 않는 제품을 연속적으로 가동시킴으로써 고장시간을 단축시키는 사용를 가속과 사용조건보다 높은 스트레스를 부과하여 제품의 수명을 단축시키는 고 스트레스 가속이 있다. 기계류 부품들에서 대부분 채택하고 있는 고 스트레스 가속방법을 적용한 무고장 가속시험의 전략은 크게 현장 운영조건하에서의 등가부하를 산출, 시험 운영조건하에서의 등가부하를 산출 그리고 보증수명에 의한 무고장 시험시간을 산출하는 3가지의 기술로 운영된다. 이러한 가속시험 전략은 기계류에 관련된 대부분의 부품 및 시스템에 적용 및 활용이 가능하다.