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Volume 42 (2016)
- Issue 6 Pages 203-
- Issue 5 Pages 163-
- Issue 4 Pages 125-
- Issue 3 Pages 89-
- Issue 2 Pages 49-
- Issue 1 Pages 2-
Volume 42, Issue 6
Displaying 1-5 of 5 articles from this issue
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Research paper
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Nao SUGIMOTO, Goichi BEN, Norio HIRAYAMA2016 Volume 42 Issue 6 Pages 203-210
Published: 2016
Released on J-STAGE: December 17, 2017
JOURNAL FREE ACCESSIn this paper, static and dynamic tensile tests of woven fabric reinforced plastic composites were carried out and strain rates from 1×10−3[1/s] to 1×102[1/s] were loaded under two tensile directions of 45-degree and 0-degree to the fabric directions with a servo hydraulic testing machine. The specimens of CFRTP, CFRP, GFRTP and GFRP were composed of respective fibers fabrics of carbon and glass and two different matrix resin of PA6 and epoxy. All of the specimens were fabricated with VaRTM process. The experimental results for the strength of 45-degrees specimens depended on the strain rates. Fracture strain of GFRTP and GFRP 45-degress specimens were not showed strain rates dependency. However, the fracture strain of CFRTP and CFRP declined with increasing strain rate. Absorbed energy of CFRTP and GFRTP 45-degrees specimen showed twice the value compared to the CFRP and GFRP in strain rate 10[1/s]. From the above results, strain rate dependency of strength, fracture strain and absorbed energy of FRTP and FRP by using woven fabric 45-degrees specimen were affected by reinforced fiber and matrix resin.View full abstractDownload PDF (4172K) -
—Fabrication of CF/PA6 Unidirectional Laminates and Evaluation of Its Flexural Properties—Hironori NISHIDA, Akira MATSUBA, Yousuke KOUNO, Toshio FUJII, Hiroyuki ...2016 Volume 42 Issue 6 Pages 211-219
Published: 2016
Released on J-STAGE: December 17, 2017
JOURNAL FREE ACCESSIn this study, a new automatic tape laying (ATL) method for CFRTP intermediate material was developed by using machine stitching, which can be effective to reduce material waste and production costs in automotive manufacturing. Narrow CF/PA6 semipreg tapes were stacked and fixed onto a sheet of PA6 base film by a modified embroidery sewing machine. Subsequently unidirectional laminates were fabricated and flexural specimens without fiber break were cut out from the non-stinging region of the laminates. The flexural properties of this tape lay-up laminates were examined under three-point bending condition in comparison with those of a laminate laid up with conventional wide width semipreg sheets. As a result, it was found that there is no significant difference in the flexural properties for the fiber direction between the tape lay-up laminates without fiber break and the conventional sheet lay-up laminate under the same fiber volume fraction. However, the flexural modulus and strength showed relatively low values in the tape lay-up laminates due to the decline of the fiber volume fraction because of the use of subsidiary materials of PA6 such as the base film and stitching thread.View full abstractDownload PDF (4569K) -
Yoshinori INOUE, Taiji IKAWA, Tomonaga OKABE2016 Volume 42 Issue 6 Pages 220-227
Published: 2016
Released on J-STAGE: December 17, 2017
JOURNAL FREE ACCESSMicromechanics models proposed by Nairn et al. and Hashin, which can treat imperfect bonded interfaces between fibers and matrix polymers, are evaluated to utilize the models for predicting accurate deformation of injection molded parts of short fiber reinforced thermoplastics. The treatment of the imperfect interfaces is essential to deal with a difference of the interface conditions which affect mechanical properties of the parts. In contrast, general micromechanics models, such as the Mori-Tanaka (MT) model, are not appropriate because a perfect bonded interface is assumed in the models. For the evaluation of the Nairn-Hashin (NH) models, we first compare the NH models with the MT model under the condition of the perfect interface. Elastic moduli calculated from the NH models almost agreed with that from the MT model. The NH models are then evaluated by using elastic moduli measured for randomly fiber-oriented films of short glass fiber reinforced polypropylene. By considering the imperfect interface parameters estimated from pull-out tests of a single glass fiber embedded in a polypropylene matrix, the NH models predicted the measured elastic moduli.View full abstractDownload PDF (1356K) -
Ryotaro OZAKI, Tatsuya KAWAMATA, Ryosuke YAMASAKI, Keiji OGI, Kazunori ...2016 Volume 42 Issue 6 Pages 228-234
Published: 2016
Released on J-STAGE: December 17, 2017
JOURNAL FREE ACCESSResistance variation and Joule heating of carbon fiber reinforced plastic after applying a large electric current pulse are investigated. The current has a pulse width of several microseconds and the typical peak value is 2 kA. A double-digit decrease in resistance of a cross-ply laminate is observed after applying the kA current pulse. The decrease in resistance of the cross-ply laminate can be controlled by varying the charge voltage in the pulse generator circuit. In the case of DC current Joule heating, the direction of heat conduction at the surface is parallel to the fiber direction of the cross-ply laminate. However, the kA current pulse locally heats in the vicinity of the electrode and the thermal profile is different from the DC current.View full abstractDownload PDF (1927K)
Technical note
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Seiichi ITO, Sunao SUGIMOTO, Tetsuya MORIMOTO, Hisaya KATOH2016 Volume 42 Issue 6 Pages 235-240
Published: 2016
Released on J-STAGE: December 22, 2017
JOURNAL FREE ACCESSDownload PDF (547K)
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