巻号一覧
26 巻 (2000)
- 6 号 p. 203-
- 5 号 p. 163-
- 4 号 p. 121-
- 3 号 p. 83-
- 2 号 p. 37-
- 1 号 p. 1-
26 巻, 4 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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津田 浩, 武田 真一, 卜部 啓, 高橋 淳, 岸 輝雄2000 年 26 巻 4 号 p. 121-129
発行日: 2000/07/15
公開日: 2009/08/11
ジャーナル フリーResponse of a Michelson Interferometric fiber-optic sensor to impact loading was investigated. A Michelson Interferometric fiber-optic sensor was mounted on the surface of unidirectionally aligned carbon fiber-reinforced epoxy composites. Using a Charpy tester, the load was applied to the specimen at two impact energy levels. One was the case where the specimen sustained no damage; another was the case where localized damage occurred in the specimen. Both the optical interference signal and the strain were measured during the impact loadings. The spectrum analysis of the interference signal was performed by the Fast Fourier Transforms. The analytical results were compared with the predicted frequency characteristics from the strain rate. In the case where damage occurred in the specimen, the interference signal recorded before and after the peak in load and during unloading had relatively high intensity in wider frequency range than that predicted from the strain rate. This discrepancy in frequency characteristics is attributed to the vibration induced by fiber breaking or crack closure. The Michelson interferometric fiber-optic sensor proved to be effective for detecting the impact damage of the material studied.抄録全体を表示PDF形式でダウンロード (7910K) -
守屋 一政, 西山 慎一郎, 本山 泰之2000 年 26 巻 4 号 p. 130-140
発行日: 2000/07/15
公開日: 2009/08/11
ジャーナル フリーExperimental tests have been conducted on the mechanical behavior of a CFRP 1×7 strand cable with a central core subjected to torsional loading. The failure process of each helical string and the core has been probed independently by means of an electrical resistance method. Unloadingreloading torsion test has also been done to investigate the effects of cyclic loading. It has been found that the torsional failure of the CFRP strand cable has two stages. The first is a compressive failure of core, which does not immediately result in a loss of load-carrying capacity, but it later induces a tensile fracture of all spiral strings, i.e. the final failure of the cable. Although the tensile strength of the CFRP strand cable is almost the same as that of the steel strand cable of the same diameter, its torsional properties are far lower than those of the steel cable. Cyclic loading causes more damage to the core than to the spiral strings and it reduces the torsional strength significantly. The electrical resistance method, which requires no external sensor, works successfully for the sensitive detection of the fiber breakage in core and spiral strings and hence, the present CFRP strand cable can be regarded as a smart structural element with health-monitoring capability.抄録全体を表示PDF形式でダウンロード (3004K) -
石川 隆司, 松嶋 正道, 林 洋一2000 年 26 巻 4 号 p. 141-151
発行日: 2000/07/15
公開日: 2009/08/11
ジャーナル フリーExtensive experimental research was conducted to pursue mechanical behavior occurred in the actual Compression-after-Impact (CAI) tests for conventional (brittle) CF/Epoxy composite plates. Two test methods, SACMA and NASA were used and examined for future possible improvements. Comparison of experimental results obtained by the two methods is another key issue in the present paper. Focuses are placed on the pursuit of mechanism of behavior during the tests. By examining the mechanics, an appropriate parameter was discovered for unified data reduction obtained by the two methods. It is based on a ratio of a virtual cylinder with an effective diameter of delamination excluding the “brim” region to a total sectional area of the specimen. CAI strengths and initial local buckling in delaminated area were universally explained by this parameter.抄録全体を表示PDF形式でダウンロード (8297K)
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