• Title, Summary, Keyword: Fiber Orientation Function

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Effects of Aspect and Area Ratio of Fiber on the Accuracy of Intensity Method in Measurement of Fiber Orientation-Angle Distribution (섬유배향각 분포측정에 있어서 농도법의 정밀도에 미치는 섬유종횡비와 면적비의 영향)

  • Lee, S.D.;Kim, H.;Lee, D.G.;Han, G.Y.;Kim, E.G.
    • 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.

Accuracy of Intersection Counting Method in Measurement of Fiber Orientation Angle Distribution Using Image Processing (화상처리에 의한 섬유배향각 분포측정에 있어서 교차점합산법의 정밀도)

  • 이상동;박준식;이동기;한길영;김이곤
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.12
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    • pp.97-105
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    • 1998
  • The fiber oriented condition inside fiber reinforced composite material is a basic factor of mechanical properties of composite materials. It is very important to meausure the fiber orientation angle for the determination of molding conditions, mechanical characteristics, and the design of composite materials. In the work, the fiber orientation distribution of simulation figure plotted by PC is measured using image processing in order to examine the accuracy of intersection counting method. The fiber orientation function measured by intersection counting method using image processing is compared with the calculated fiber orientation function. The results show that the measured value of fiber orientation function using intersection counting method is lower than the calculated value, because the number of intersection between the scanning line and the fiber with smaller fiber aspect ratio is counted less than with larger fiber aspect ratio.

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Measurement of Fiber Orientation-Angle Distribution of Glass Fiber Reinforced Polymeric Composite Materials by Intensity Method (농도법에 의한 GFRP 복합재료의 섬유배향각 분포측정)

  • Kim, H.;Ann, J.Y.;Lee, D.G.;Han, G.Y.;Kim, E.G.
    • 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.

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Effect of Fiber Content and Fiber Orientation on the Tensile Strength in Glass Mat Reinforced Thermoplastic Sheet (GMT Sheet에서 섬유함유율 및 섬유배향이 인장강도에 미치는 영향)

  • Lee, Jung-Ju;Lee, Dong-Gi;Sim, Jae-Ki;Jo, Seon-Hyung;Kim, Jin-Woo
    • Proceedings of the KSME Conference
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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.

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Effect of Fiber Orientation on the Tensile Strength in Twisted Yarn Composites (Twisted Yarn 복합재료에서 인장강도에 미치는 섬유배향의 영향)

  • Lee, Dong-Ki;Sim, Jae-Ki;Kim, Hyuk;Kim, Jin-Woo;Lee, Jung-Ju;Lee, Ha-Wook
    • Proceedings of the Korean Society of Precision Engineering Conference
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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.

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A Study on the Fiber Orientation and Fiber Content Ratio Distribution during the Injection Molding for FRP (FRP의 사출성형에 있어서 섬유배향상태와 섬유함유율분포에 관한 연구)

  • Kim J. W.;Lee D. G.
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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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.

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Effect of Fiber Orientation and Fiber Contents on the Tensile Strength in Fiber-reinforced Thermoplastic Composites (섬유배향과 섬유함유량이 섬유강화 열가소성수지 복합재료의 인장강도에 미치는 영향)

  • Kim, Jin-Woo;Lee, Dong-Gi
    • Composites Research
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    • v.20 no.5
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    • pp.13-19
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    • 2007
  • Fiber-reinforced thermoplastic composites not only approach almost near to the strength of thermosetting composite but also has excellent productivity, recycling property, and impact resistance, which are pointed as weaknesses of thermosetting composites. The study for strength calculation of one direction fiber-reinforced thermoplastic composites and the study measuring precisely fiber orientation distribution were presented. Need the systematic study for the data base that can predict mechanical properties of composite material and fiber orientation distribution by the fiber content ratio was not constructed. Therefore, this study was investigated what affect the fiber content ratio and fiber orientation distribution have on the strength of composites. Fiber-reinforced thermoplastic composites by changing fiber orientation distribution and the fiber content ratio were made. Tensile strength ratio of $0^{\circ}$ direction of fiber-reinforced composites increased being proportional the fiber content and fiber orientation function as change from isotropy(J=0) to anisotropy(J=1). But, tensile strength ratio of $90^{\circ}$ direction by separation of fiber filament decreased when tensile load is imposed fur width direction of reinforcement fiber length direction.

Effect of Mold Temperature on the Separation and the Orientation during Compression Molding of Fiber-Reinforced Polymeric Composites (섬유강화 고분자 복합재료의 압축성형에 있어서 분리 ${\cdot}$ 배향에 미치는 금형온도의 영향)

  • Lee, Dong-Gi;Han, Gil-Young;Kim, E-Gon
    • Journal of Ocean Engineering and Technology
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    • v.9 no.2
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    • pp.123-132
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    • 1995
  • During compression molding of fiber-reinforced polymeric composites, microstructural changes such as the fiber-matrix separation and the fiber orientation are occurred by the flow of composite materials. Since the nonhomogeneity and anisotropy of composites are caused by the separation and orientation of fibers. On the other hand, the separation and the orientation of fibers are inseparably related to each other. 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 measured by the image processing using soft X-rayed photograph and image scanner. We study effects of the mold temperature on the degree of nonhomogeneity and the orientation function.

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Accuracy Comparison between Intensity Method and Count Method in Measurement of Planar Orientation of Fibers Using Image Processing (화상 처리를 이용한 섬유 배향각 분포 측정에서 농도법과 카운트법의 정확도 비교)

  • Lee, S.D.;Kim, H.;Lee, D.G.;Han, G.Y.;Kim, E.G.
    • Journal of the Korean Society for Nondestructive Testing
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    • v.18 no.5
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    • pp.357-364
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    • 1998
  • To investigate accuracies between intensity method and count method for measurement of the fiber orientation distribution, fiber orientation function is derived by drawing simulation figure 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 and count method are compared with the calculated ones from simulation figures. The results show that measurement accuracy of fiber orientation angle distribution obtained by count method is by 4% higher than that by intensity method.

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Fiber orientation in the processing of polymer composites

  • Chung, Du-Hwan;Kwon, Tai-Hun
    • Korea-Australia Rheology Journal
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    • v.14 no.4
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    • pp.175-188
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    • 2002
  • We review the modeling and simulation of fiber orientation during injection molding processes of short fiber reinforced thermoplastics. Generally, a group of fibers are described in terms of probability distribution function or orientation tensor. Various closure approximation models to express higher order tensor in terms of Bower order tensors are reviewed. Rheology of fiber suspensions, multiple fiber-fiber interaction and numerical technique for the prediction of fiber orientation are also considered for concentrated situations.