• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.1
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• pp.109-118
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• 1985

특이응력해석을 위한 일반화된 가역상반일 경계분식이 섬유강화복합재를 모형화한 직교 이방성 크랙평판의 수치해를 위하여 발전시켰다. 이 적분방정식은 평판경계에서의 탄성변위와 트랙션의 변수로 구성된 경계분식의 형태로 하중이 없다는 두 크랙면의 경계조건과 유한의 탄성변형에너지 의 개념에서 경계적 분식에 필요한 특성해를 규정하고 대응되는 보조해를 계산하였다. 직교이방 도를 달리한 중앙크랙평판의 응력확대계수를 계산하여 기존해와 비교하였다. 또한 대칭모우드 I 형의 양측크랙평판 및 복합모우드형 편측크랙 일단고정 평판의 응력확대계수가 임의의 섬유방향 각에 따라서 계산되었다.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1998.10a
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• pp.330-336
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• 1998

The friction and wear characteristics of automotive friction materials reinforced with carbon fibers were studied using a direct drive brake dynamometer. Two types of model friction materials, a low-metallic and an NAO type, were prepared and each of the materials was modified by substituting 5 vol% of carbon fibers with other reinforcing fiber used in the model formulations. Drag tests were carried out to investigate the friction properties of these materials at various braking conditions. Results showed that the modified friction materials were improved in the friction stability and the wear resistance.

• Korean Journal of Materials Research
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• v.7 no.9
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• pp.795-804
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• 1997

전면재를 알루미나, 후면재를 Kevlar또는 S-2 유리 섬유강화 복합재료로 접합한 이종재료 장갑에 대하여 알루미나의 두께 변화와 복합재료의 적층구조에 따른 고속충격 특성 변화에 대하여 연구하였다. 또한 시험재료의 동적 관통현상을 분석하기 위하여 고속촬영기법이 이용되었다. 시험결과, 전면재인 알루미나는 충격탄자 직경의 80% 상당하는 두께(본 실험에서는 6nm)인 경우 양호한 방탄성능을 보였다. 후면재인 복합재료는 섬유를 alternating 주조로 적층한 경우가 laminar구조로 적층한 것에 비하여 더 우수한 방탄성능을 나타내었다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.6
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• pp.41-48
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• 2000

The Compression molding process is widely used in the automotive industry to produce parts that are large, thin, light-weight, strong and stiff. Compression molded parts are formed by squeezing a glass fiber reinforced polypropylene sheet, known a glass mat thermoplastic(GMT), between two heated cavity surfaces. In this study, the anisotropic viscosity of the Unidirectional Fiber-Reinforced Plastic Composites is measured using the parallel plastometer and the composites is treated as an incompressible Newtonian fluid. The effects of molding parameter and fiber contents ratio on longitudinal/transverse viscosity are also discussed.

• Defense and Technology
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• no.9 s.163
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• pp.46-50
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• 1992

고온, 고압의 추진제 연소가스로부터 노즐 구조물을 보호하기 위해 사용되는 열 차폐용 삭마성 내열재료(ablative material)의 종류와 재료선정을 위한 시험방법, 설계 및 제작기법, 성능평가 기준 등에 관한 연구동향을 검토하고 본 연구팀의 연구결과를 제시하였습니다 고체추진제 연소 환경하에서의 노즐 보호재료로서는 고분자계 삭마성 내열재가 주로 사용되는데, 이 ablative material에는 여러 종류가 있으나 높은 heat flux와 빠른 mass flow에 대한 내열을 위해서는 페놀, 폴리이미드 등 열경화성 수지인 charring material이 모재로 주로 사용되며 강도향상을 위해서 탄소, 실리카, 석면, 유리등의 강화섬유가 보강재로 사용됩니다 현재는 모재로서 고분자계 수지외에도 세라믹과 같은 무기재료, 금속재료등과 강화섬유를 조합하여 내열성과 강도가 향상된 재료를 개발하는 연구도 진행되고 있습니다

• Journal of Power System Engineering
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• v.10 no.4
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• pp.133-138
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• 2006

Effective thermal conductivity of particulate reinforced composite has been predicted by Eshelby's equivalent inclusion method modified with Mori-Tanaka's mean field theory. The predicted results are compared with the experimental results from the literature. The model composite is polymer matrix filled with ceramic particles such as silica, alumina, and aluminum nitride. The preliminary examination by Eshelby type model shows that the predicted results are in good agreements with the experimental results for the composite with perfect spherical filler. As the shape of filler deviates from the perfect sphere, the predicted error increases. By using the aspect ratio of the filler deduced from the fixed filler volume fraction of 30%, the predicted results coincide well with the experimental results for filler volume fraction of 40% or less. Beyond this fraction, the predicted error increases rapidly. It can be finally concluded from the study that Eshelby type model can be applied to predict the thermal conductivity of the particulate composite with filler volume fraction less than 40%.

• Journal of Distribution Research
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• v.11 no.3
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• pp.23-53
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• 2006

Brands are important in the consumer market. They are the interface between consumers and the company. And consumers may develop loyalty to brands. Also, the late development of industrial marketing explains the near absence of research on brand equity in business to business. With recent change, Industrial companies have shifted from a production focus to a customer focus. Industrial brand is fast developing. The basic purpose of this study is to investigate industrial brand trust and loyalty affecting the result of business relationship between industrial buyers and suppliers. Factors hypothesized to influence trust in a brand include a number of brand characteristics, company characteristics and consumer-brand characteristics. This research presented a comprehensive constructive model consisting of components of industrial brand trust and loyalty, and then propose the research model base on prior researches and studies about relationships among components of industrial brand loyalty Data were gathered from respondents who work in industrial buying center. For this study, Data were analyzed by AMOS 4.0. The results of this research analysis were as fallow. Industrial brand trust and loyalty were positively related with a number of industrial brand characteristics, supplier characteristics and buyer-brand characteristics, relationship commitment. This research newly proposed the concept of industrial brand trust and loyalty affecting the result of business relationship between industrial buyers and suppliers.

• Composites Research
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• v.26 no.5
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• pp.322-327
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• 2013

Carbon fiber-reinforced SiC matrix composites have good oxidation resistance and thermal shock resistance. These properties have allowed the composites to be applied to high-temperature structures. In this study, $C_f/SiC$ composites were fabricated via precursor infiltration and pyrolysis (PIP) process, including liquid phase infiltration and chemical vapor curing using cyclohexene. The final $C_f/SiC$ composites, which have gone through the PIP process five times, showed a density of $1.79g/cm^3$, as compared to a density of $0.43g/cm^3$ for pre-densified bare carbon fiber preform. As for the oxidation resistance characteristics, the weight of $C_f/SiC$ composite was maintained at 81% at $1400^{\circ}C$ in air for 6 hours. Chemical vapor curing (CVC) using cyclohexene has shown to be an effective method to achieve high densification, leading to increased oxidation resistance.

• Journal of the Korean Wood Science and Technology
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• v.31 no.5
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• pp.23-34
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• 2003

This study was carried out to investigate the mechanical properties of fabric E-glass fiber reinforced laminated timber. Specimens used to Korean red pine(Pinus densiflora) and Japanese larch(Larix kaemferi). Fabric E-glass fiber was inserted in the solid wood with aqueous polymer-isocyanate resin(MPU-500). The results were as follows: 1. Aqueous polymer-isocyanate resin(MPU-500) was good resin to manufacture laminated timber. specially, it was satisfied to property standard of construction laminated timber(KS F 3021) except for two ply glass fiber. 2. Bending and shear strengths of solid wood inserted with fabric glass fibers were not different from control solid wood. But, proportional limit bending stress was increased following the number of fabric glass fibers. Therefore, it was considered that to improve the bending and shear strength of fabric glass fiber reinforced laminated timber, the glass fiber thickness and its mesh should be modified to fitness following working conditions.

• Restorative Dentistry and Endodontics
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• v.32 no.2
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• pp.111-120
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• 2007

The purpose of this study is to evaluate the effects of surface treatment and composition of reinforcement material on fracture strength of fiber reinforced composite inlay bridges. The materials used for this study were I-beam, U-beam TESCERA ATL system and ONE STEP(Bisco, IL, USA). Two kinds of surface treatments were used; the silane and the sandblast. The specimens were divided into 11 groups through the composition of reinforcing materials and the surface treatments. On the dentiform, supposing the missing of Maxillary second pre-molar and indirect composite inlay bridge cavities on adjacent first pre-molar disto-occlusal cavity, first molar mesio-occlusal cavity was prepared with conventional high-speed inlay bur. The reinforcing materials were placed on the proximal box space and build up the composite inlay bridge consequently. After the curing, specimen was set on the testing die with ZPC. Flexural force was applied with universal testing machine (EZ-tester; Shimadzu, Japan). at a cross-head speed of 1 mm/min until initial crack occurred. The data was analyzed using one-way ANOVA/Scheffes post-hoc test at 95% significance level. Groups using I-beam showed the highest fracture strengths (p<0.05) and there were no significant differences between each surface treatment (p>0.05) Most of the specimens in groups that used reinforcing material showed delamination. 1. The use of I-beam represented highest fracture strengths (p<0.05) 2. In groups only using silane as a surface treatment showed highest fracture strength, but there were no significant differences between other surface treatments (p>0.05). 3. The reinforcing materials affect the fracture strength and pattern of composites inlay bridge. 4 The holes at the U-beam did not increase the fracture strength of composites inlay bridge.