• 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 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.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.186-191
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• 2004

we can say that the increasing range of the value of GMT Sheet's tensile strength in the direction of fiber orientation is getting wider as the fiber content increases. It shows that the value of GMT Sheet's tensile strength in the direction of fiber orientation 90 is similar with the value of pp's intensity when fiber orientation function is J= 0.7, regardless of the fiber content. Tensile strength of GMT Sheet is affected by the fiber orientation distribution more than by the fiber content.

• Proceedings of the Korean Fiber Society Conference
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• 1998.10a
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• pp.418-421
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• 1998

실의 역학적 특성은 실을 구성하고 있는 섬유의 역학적 특성은 물론 실의 구조적 특성에 의존한다. 실의 구조적 특성은 구성 섬유의 경로에 따라서 결정이 되는데 지금까지는 주로 이상 나선 구조 모델로 가정한 후 실의 역학적 특성을 고찰하여 왔다[1]. 그러나 실제로 꼬임이 있는 실을 방출할 경우 꼬임을 부여하는 과정에서 구성 섬유들 간에 걸리는 장력의 차이에 의하여 섬유들은 실의 외부에서 내부로 또는 내부에서 외부로 이동하게 된다. (중략)

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.252-257
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• 2005

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation' orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line in injection-molded products is assessed. And the effects of fiber content and injection mold-gate conditions on the fiber orientation are also discussed.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.2
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• pp.104-113
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• 1993

Characteristics of fiber-reinforced thermoplastic sheet depend on the quantity and shape of fibers. During a molding process of composites, the fiber-maxtrix separation and fober orientation are caused by the flow during the molding process. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation-orientation and molding conditions. The correlation between the separation and the orientation have to be clarified for designing the fiber structure. In this paper, the degree of nonhomogeneity which is a measure of the separation is obtained using one-dimensional rectangular shaped part compression molding. And the orientation function is defined and measured by the image processing using soft X-rayed photograph and image scammer. Correlation between the degree of nonhomogeneity and the orientation function is discussed.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.6
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• pp.34-44
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• 1996

In order to examine the accuracy of the intensity method, the fiber orientation-angle distribution of fiber-reinforced polymeric composites is measured using image processing. The fiber orientation function is calculated from the fiber orientation measured by the soft X-ray photograph. Theoretical and experimental results of fiber orientation function are compared for the composites with different fiber contents and fiber orientations. The intensity method is used for the experimental investigation and the measured fiber orientation function is compared to the calculated one. The relations between the measured and the simulated fiber orientation functions $J{\small{M}}$ and $J{\small{S}}$ respectively are identified. For the fiber length of 1.000mm and 2.000mm, it shows that $J{\small{M}}=0.83J{\small{M}}$. However. in general. the value of $J{\small{M}}$ decreases as the fiber length increases. For GFRP composites the relations between $J{\small{M}}$ and theoretical value J show that $J{\small{M}}$=0.73J for short fiber and $J{\small{M}}$=0.81J for long fiber.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2000.11a
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• pp.265-270
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• 2000

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation· orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line parts in injection-molded products is assessed. And the effects of fiber content and injection molding conditions on the fiber orientation functions are also discussed

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.4
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• pp.953-959
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• 1998

To investigate accuracy of intensity method for measurement of the fiber orientation distribution, fiber orientation function is calculated by drawing simulation figures for the fiber orientation as varying fiber aspect ratio, fiber area ratio, and fiber orientation state, respectively. The values of fiber orientation function measured by intensity method are compared with the calculated values of fiber orientation function. The results show that measurement accuracy of the fiber orientation angle distribution by intensity method is affected by the fiber aspect ratio when the total length of oriented fiber is same. The average gradient of fiber orientation function is 0.94 for 1000mm of the total fiber length and is 0.93 for 2000 mm when the fiber aspect ratio is over 50. Measurement accuracy by intensity method is about 94% and the reliable data can be obtained by intensity method.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.4
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• pp.1-7
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• 2006

Injection molding is a very important industrial process for the manufacturing of plastics objects. During an injection molding process of composites, the fiber-matrix separation and fiber orientation are caused by the flow of molten polymer/fiber mixture. As a result, the product tends to be nonhomogeneous and anisotropic. Hence, it is very important to clarify the relations between separation orientation and injection molding conditions. So far, there is no research on the measurement of fiber orientation using image processing. In this study, the effects of fiber content ratio and molding condition on the fiber orientation-angle distributions are studied experimentally. Using the image processing method, the fiber orientation distribution of weld-line in injection-molded products is assessed. And the effects of fiber content and injection mold-gate conditions on the fiber orientation are also discussed.