• Proceedings of the Korean Society For Composite Materials Conference
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• 2004.04a
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• pp.284-287
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• 2004

After we experiment one direction fiber reinforced composites$(\theta\;=\;0^{\circ},\;J=1)$ to the X direction$(\theta\;=\;0^{\circ},\;J=1)$, we can say that fiber orientation efficiency and fiber orientation angle efficiency become lower. It is because the more the fabric is orientated in a equal direction with one direction fiber floor the more the load given from the exterior becomes shear rather than tension, even though one direction fiber floor gets the most of the exterior power. when fiber content ration is $10wt\%$, the fiber reinforcement efficiency of J=0.3 is similar with the fiber reinforcement efficiency of $\theta=30^{\circ}$ We also found that the fiber reinforcement efficiency of J=0.2 is similar with the fiber reinforcement efficiency of $\theta=20^{\circ}$ in case of $20wt\%$.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.55-60
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• 2003

Case that long-fiber reinforced polymeric composites of fiber orientation situation of a direction state is J=1 that is direction of tensile strength of another state appeared highest. And theoretical tensile strength value of long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state appeared similarly with tensile strength value that long-fiber reinforced polymeric composites board of fiber orientation situation of a direction state. Also, than case that efficiency of fiber orientation situation of long-fiber reinforced polymeric composites is J=1 in it is J=0.1 of fiber orientation situation effect of long-fiber reinforced polymeric composites about 60% high appear.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2003.04a
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• pp.202-205
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• 2003

Investigated whether fiber orientation situation of fiber reinforcement macromolecule composition board and the fiber inclusion rate are perpendicular and horizontal direction tensile strength and some correlation. Fiber orientation situation of tensile strength of 0 direction of composition board increased changelessly by aeolotropy in isotropy. Tensile strength of 90 direction that is isotropy and tensile strength of 0 direction that is aeolotropy agreed almost. Get into aeolotropy, the reinforcement rate of fiber decreased. When load interacts for width direction of reinforcement.

• Journal of Ocean Engineering and Technology
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• v.10 no.3
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• pp.34-43
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• 1996

In this study basic equations of fiber orientations is cimpared with experimental results. It is found that fiber orientations of short fiber reinforced polymeric composite under compression molding are governed by slope of flow speed in x-y direction. Fiber orientation angle of mold is also found to increase with closure speed and the compression ratio. At the middle of the mold, the slope of flow speed is larger in x-direction than in y-direction. At the wall of the mold, the shope of flow speed in y-direction occurs due to the effect of friction, hence affects the fiber orientation. The effect of partial flow, which incurs y-direction orientation causes to increase the fiber orientation angle at the fore part of the flow.

• Tribology and Lubricants
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• v.36 no.3
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• pp.133-138
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• 2020

In this paper, we present an experimental investigation of the friction coefficient and wear area change of carbon/epoxy and E-glass/epoxy composites depending on the fiber direction (0°/90°). We compared the results of the case where the sliding direction is parallel to the fiber direction (0°) with that of the case where it is perpendicular to the fiber direction (90°). The ball-on-plate wear test equipment was used to cause wear in both directions. Two types of specimens were prepared with thicknesses of 3 mm-one made of carbon fiber reinforced plastic composite (CFRP) and the other of glass fiber reinforced plastic composite (GFRP). A normal force of 20 N was applied to the specimen and the sliding speed was 10 mm/s and the sliding distance was set to 20 m to perform the wear test. The CFRP demonstrates superior tribological characteristics compared to the GFRP. This outcome is attributed to graphitization of carbon, which serves as solid lubricating particles. In addition, both CFRP and GFRP are worn more in the 90° direction than in the 0° direction. This is due to the greater occurrence of fiber breakage and separation in the 90° direction than in the 0° direction. This study is expected to be utilized as basic data for understanding the friction and wear characteristics of CFRP and GFRP composites along the fiber direction and to apply the appropriate material.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.199-204
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• 1998

In this study, a method is presented which can be used to measure the fiber orientation distribution for thickness direction during injection molding using image processing. The intensity method in used for measuring the distribution. And the effects of fiber content, injection molding condictions on the orientation function are also discussed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.422-425
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• 2003

Investigated whether fiber orientation distribution of twisted yarn composites and the fiber content are 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength and some correlation. Tensile strength of 0$^{\circ}$ directions of twisted yarn composites increased changelessly being proportional the fiber content and fiber orientation function get into anisotropic in isotropic. But, tensile strength ratio by separation of fiber filament of 90$^{\circ}$ directions tensile strength decreased when tensile load is imposed for width direction of reinforcement fiber. 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio value of a twisted yarn composites not receive almost effect of the fiber content of fiber orientation function J = 0.4 lows. Although do, 20 wt% of the fiber content is high about 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio about 1.6~2 than 10 wt% from J = 0.4. Therefore. could know that effect of the fiber content is dominate.

• Elastomers and Composites
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• v.50 no.3
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• pp.184-188
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• 2015

There is a need for light weight and high stiffness characteristics in the building structure as well as aircraft and cars. So fiber reinforced plastic with the addition of reinforcing agent such as glass fiber, carbon fiber, aramid fiber is utilized in this regard. In this study, mechanical strength, flow property and part shrinkage of glass fiber and carbon fiber reinforced PA6 were examined according to reinforcement content such as 10%, 20%, and 30%, and reinforcement type. The mechanical property was measured by a tensile test with specimen fabricated by injection molding and the flow property was measured by spiral test. In addition, we measured the part shrinkage of fiber reinforced PA6 that affects part quality. As glass fiber content increases, mechanical property increased by 75.4 to 182%, and flow property decreased by 18.9 to 39.5%. And part shrinkage decreased by 52.9 to 60.8% in the flow direction, and decreased by 48.2 to 58.1% in the perpendicular to the flow direction. As carbon fiber content increases, mechanical property increased by 180 to 276%, flow property decreased by 26.8 to 42.8%, and part shrinkage decreased by 65.0 to 71.8% and 69.5 to 72.7% in the flow direction and the direction perpendicular to the flow respectively.

• Journal of the Korea Institute of Building Construction
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• v.11 no.4
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• pp.326-332
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• 2011

Carbon, Aramid, Boron and Glass fibers are used as fibrous materials to promote structural bearing strength. Of these fiber types, carbon fiber is the most commonly used material, and is characterized by having a one-way direction, which is strengthened by tensile strength due to the attached direction only, while other types of fibers are two-way. Therefore, when applied in the field, the attachment direction of fiber is a very important factor. However, when fiber direction is not mentioned in the design drawing, there sometimes is no improvement in structural strength, as the fiber is being installed by a site engineer or workers who lack structural knowledge. The purpose of this study was to propose an optimal direction of carbon fiber through a comparison & analysis of reinforcing efficiency with reinforced experimental columns that used carbon fibers in each of the inclined, horizontal and vertical directions. According to the results, horizontal direction in the reinforced column was improved by 153.43%, but vertical direction was 104.61% only, and it was understood this was due to increased tensile strength along the fiber direction. For this reason, it is necessary to include information regarding fiber direction in design and site management.

• Restorative Dentistry and Endodontics
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• v.34 no.4
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• pp.364-370
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• 2009

The aim of this study was to evaluate the effect of fiber direction on the polymerization shrinkage of fiber-reinforced composite. The disc-shaped flowable composite specimens (d = 10 mm, h = 2 mm, Aeliteflo A2, Bisco, Inc., IL, USA) with or without glass fiber bundle (X-80821P Glass Fiber, Bisco, Inc., IL, USA) inside were prepared, and the longitudinal and transversal polymerization shrinkage of the specimens on radial plane were measured with strain gages (Linear S-series 350${\Omega}$, CAS, Seoul, Korea). In order to measure the free polymerization shrinkage of the flowable composite itself, the disc-shaped specimens (d = 7 mm, h = 1 mm) without fiber were prepared, and the axial shrinkage was measured with an LVDT (linear variable differential transformer) displacement sensor. The cross-section of the polymerized specimens was observed with a scanning electron microscope to examine the arrangement of the fiber bundle in composite. The mean polymerization shrinkage value of each specimen group was analyzed with ANOVA and Scheffe post-hoc test (${\alpha}$=0.05). The radial polymerization shrinkage of fiber-reinforced composite was decreased in the longitudinal direction of fiber, but increased in the transversal direction of fiber (p<0.05). We can conclude that the polymerization shrinkage of fiber-reinforced composite splint or restoratives is dependent on the direction of fiber.