日本複合材料学会誌
Online ISSN : 1884-8559
Print ISSN : 0385-2563
ISSN-L : 0385-2563
31 巻, 6 号
選択された号の論文の5件中1~5を表示しています
  • 層内き裂の多層累積挙動
    横関 智弘, 青木 隆平
    2005 年 31 巻 6 号 p. 241-250
    発行日: 2005/11/15
    公開日: 2009/08/11
    ジャーナル フリー
  • 工藤 亮, 守屋 一政, 鈴木 義久
    2005 年 31 巻 6 号 p. 251-257
    発行日: 2005/11/15
    公開日: 2009/08/11
    ジャーナル フリー
    CFRP composite patches have been widely used to repair damaged structural components of metallic aircrafts. Though CFRP is well-known as a corrosion-resistant material, once the carbon fibers of CFRP are in direct contact with aluminum alloy, the galvanic interaction between CFRP and aluminum induces the corrosion of aluminum alloy resulting decrease of the joint strength. In this study, tensile specimens made of two pieces of aluminum alloy plates joined with a single-lap cocured patch of unidirectional CFRP prepreg were immersed in salt water for 49 days maximum. For some of the specimens, silicon sealant was applied around the edge of the joint for waterproofing. Every 7 days of immersion, changes in electric potential and in electric resistance were measured followed by the tensile testing. After 49 days of immersion, the joint strength of sealed specimen was found to be more than four times higher than that of unsealed one. The relationship of the joint strength with the change in electric potential and that with the change in electric resistance were obtained. The joint strength was successfully estimated by the change in electric potential and electric resistance.
  • 高次連成フラッタ問題における解空間近似手法の検討
    平野 義鎮, 轟 章
    2005 年 31 巻 6 号 p. 258-267
    発行日: 2005/11/15
    公開日: 2009/08/11
    ジャーナル フリー
    The fractal branch and bound method has been developed by the authors for optimization of stacking sequences to maximize buckling load of composite structures. The method demands approximation of a design space with a response surface comprising quadratic polynomials for pruning fractal branches of stacking sequences. The approximation of the design space with quadratic polynomials has been confirmed for the buckling load maximization and flutter speed limit maximization using lamination parameters as predictors. In the present study, flutter speed maximization for clamped panel flutter problem is employed as an example of stacking sequence optimization by means of the fractal branch and bound method for the flutter problem, which has complicated design space due to coupling of high-order vibration modes of flutter. The theoretical background of the Fractal branch and bound method, and the modified response surface method with newly proposed the adjusted coefficient of evaluation Eadj2 (E-square-adjusted) for complicated design-spaced problem is proposed; approximation using quadratic polynomials with lamination parameters as predictors. After that, the effectiveness of the method for the supersonic clamped panel flutters of composite laminates is investigated. As a result, the method is successfully applied, and the practical optimal stacking sequence is obtained using modified response surfaces.
  • 横関 智弘, 武田 真一, 小笠原 俊夫, 石川 隆司
    2005 年 31 巻 6 号 p. 268-273
    発行日: 2005/11/15
    公開日: 2009/08/11
    ジャーナル フリー
    Corrugated-form composites manufactured from carbon fiber plain woven fabrics are expected to show ultra-anisotropic characteristics, which means very flexible in the corrugation direction and stiff in the direction perpendicular to the corrugation. In this study, mechanical properties of the corrugated composites were investigated as a candidate material of flexible structural components, e.g. morphing wings. In-plane stiffness and strength of the corrugated composites were evaluated through the tensile and bending tests in both in-plane longitudinal and transverse directions to the corrugation. Experimental results indicated that corrugated fabrics have ultra-high longitudinal/transverse stiffness ratio under tensile and bending loadings. Finally, a simple analytical model for the initial stiffness of the corrugated woven fabrics was developed, and the validity of the predic-tions was verified compared with the experimental results.
  • 2005 年 31 巻 6 号 p. 275
    発行日: 2005年
    公開日: 2010/02/08
    ジャーナル フリー
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