巻号一覧
34 巻 (2008)
- 6 号 p. 211-
- 5 号 p. 173-
- 4 号 p. 133-
- 3 号 p. 95-
- 2 号 p. 51-
- 1 号 p. 3-
34 巻, 3 号
選択された号の論文の3件中1～3を表示しています
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研究論文
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荒尾 与史彦, 小柳 潤, 八田 博志, 川田 宏之2008 年 34 巻 3 号 p. 95-101
発行日: 2008年
公開日: 2010/06/10
ジャーナル フリーMoisture absorption behavior of CFRP and its effect on dimensional stability was examined. Moisture diffusivity in CFRP was determined by measuring specimen weight during the moisture absorption test. Three types of CFRP specimens, unidirectionally reinforced, quasi-isotropically laminated and cloth-laminated composites were prepared. Each CFRP was processed into two geometries; a thin plate for determination of diffusion constants and a rod with square cross-section for the discussion of two-dimensional diffusion behavior. Coefficient of moisture expansion (CME) was also obtained from specimen deformation involving moisture absorption. During moisture absorption, the specimen surfaces strongly deformed especially near the edges because of three-dimensional moisture concentration distribution. This deformation was reasonably predicted by the finite element analysis using diffusion constants and CME, which have been experimentally determined. For unidirectional CFRP, an effect of fiber location distribution on CME is discussed by a micromechanical FEA.抄録全体を表示PDF形式でダウンロード (883K) -
日下 貴之, 渡辺 圭子, 北條 正樹, 福岡 俊康, 石橋 正康2008 年 34 巻 3 号 p. 102-108
発行日: 2008年
公開日: 2010/06/10
ジャーナル フリーThe mode I interlaminar fracture behavior of the composite laminates reinforced with Zanchor process which is a novel through-the-thickness reinforcement technique developed by Mitsubishi Heavy Industries and Shikibo, was studied on the basis of the experimental results using DCB (Double Cantilever Beam) specimens. The effects of the Zanchor reinforcement on the macroscopic fracture toughness and microscopic fracture morphology were mainly focused on. Experimental results demonstrated that the mode I interlaminar fracture toughness was remarkably improved by the Zanchor reinforcement, where the fracture toughness, GIC, increased almost linearly with the Zanchor density, Z. In addition, the fracture toughness, GIC, increased drastically during the early stage of crack growth in the Zanchor reinforced composites, where the interlaminar crack propagated stably accompanied by a large amount of fiber bridgings. The above results suggested that the increase in mode I fracture toughness was the consequence of the fiber bridgings induced by the Zanchor process. The fracture toughness, GIC, could be precisely calculated by using the chord compliance, Cchord, though obvious nonlinearity was observed in the load-displacement responses of DCB specimens.抄録全体を表示PDF形式でダウンロード (1915K) -
小野 裕, 青木 隆平, 小笠原 俊夫2008 年 34 巻 3 号 p. 109-117
発行日: 2008年
公開日: 2010/06/10
ジャーナル フリーThough excellent performances in various properties of carbon nanotubes (CNT) are widely recognized, existing reports on the mechanical properties of their composites are not as favorable as being expected. Focusing on the tensile stiffness of CNT composites, factors that may possibly be linked with the performance degradations are evaluated. These factors include CNT distribution orientation, its aspect ratio and waviness, and CNT/resin interface properties. The micromechanics inclusion model based on Eshelby tensor, combined with Mori-Tanaka theorem is adopted in this study. The spatial orientation distribution does affect the composite stiffness, tendency of which is predictable. The aspect ratio of the CNT has relatively small effect on the stiffness, whereas the impact of waviness change is drastic, which may result in as high as 40% reduction with the waviness ratio of 0.1. The effect of interface property may depend on the way it is modeled, but the numerical results suggest that the interface bonding characteristics is one of the major issues to be focused on.抄録全体を表示PDF形式でダウンロード (625K)
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