巻号一覧
41 巻 (2015)
- 5 号 p. 149-
- 4 号 p. 106-
- 3 号 p. 75-
- 2 号 p. 47-
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41 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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長塚 渉, 松尾 剛, 村上 岳, 平野 啓之2015 年 41 巻 3 号 p. 75-84
発行日: 2015年
公開日: 2016/06/03
ジャーナル フリーIt is important to understand the contribution of out-of-plane properties in order to clarify the bending deformation of out-of-plane anisotropic material like the CFRTP (carbon fiber reinforced thermoplastics) in detail. The out-of-plane mechanical properties of CFRTP would be affected by matrix resin. So the analysis of the temperature-dependence of the matrix resin will be a very important. And a method for predicting the temperature-dependence of bending behavior is greatly helpful to the wide use of CFRTP. From this point of view, in this study, the theoretical model of temperature-dependent flexural elastic modulus of CFRTP focusing on viscoelastic properties of matrix resin was constructed and verified by use of polypropylene-based discontinuous CF mat reinforced thermoplastics (CMT) with in-plane isotropic. As a result, it was quantitatively clarified that the temperature-dependence of flexural modulus of CMT is due to viscoelastic property of matrix resin. And the contribution of out-of-plane shear modulus G13c to flexural modulus was also clarified quantitatively. These results indicate that the temperature-dependence of flexural modulus of CMT was able to be predicted by Young′s modulus E1c and out-of-plane shear modulus G13c influenced from viscoelastic property of matrix resin, volume fraction of fiber and coefficient configuration of fiber reinforcement by using the ordinary measurement method.抄録全体を表示PDF形式でダウンロード (1601K) -
跡部 哲士, 村本 真人, 胡 寧, 福永 久雄2015 年 41 巻 3 号 p. 85-93
発行日: 2015年
公開日: 2016/06/03
ジャーナル フリーThis paper presents the identification of impact forces acting on sandwich panels, and also the detection of the impact-induced damage based on the identified impact force. In the present study, the impact location and the force history are identified using the radiated sound at impact which is measured with microphones. The impact location is identified using the differences in the arrival times of the sound wave at the microphones. The force history is determined from the measured sound pressure using the identification method based on experimental transfer matrices. Here, the experimental transfer matrix expresses the relationship between the applied impact force and the measured sound pressure, and it is constructed based on the measured data obtained by conducting preliminary impact tests. The damage occurrence is judged by examining the identified force history for the presence of sharp drops and small fluctuations due to damage propagation. The validity of the proposed method is verified experimentally with a sandwich panel composed of CFRP facesheets and an aramid honeycomb core by conducting impact tests using an impulse hammer. The results reveal that the location and force history of the applied impact can be identified accurately by using the radiated sound even when damages are induced within the structure. In addition, it is shown that the occurrence and location of the damage can be estimated in real time from the identified impact force.抄録全体を表示PDF形式でダウンロード (1610K) -
末益 博志, 滝澤 慎太郎, 森本 哲也, 北條 正弘2015 年 41 巻 3 号 p. 94-101
発行日: 2015年
公開日: 2016/06/03
ジャーナル フリーAn interlaminar tensile strength of the CFRP laminates was measured following a test method (ASTM D 6415). L-shape specimens having three different corner curvatures were prepared and loaded by 4 point bending setup. The tested data were analyzed by supposing that the delamination started from a defect where the interfacial stress first exceeded its strength. The defect was assumed a spatial Poisson process. The expected number of the defects in a unit area which were weaker than an interlaminar tensile stress was assumed to follow a power form of the stress. By using the assumption, we were able to find two material properties under the condition that the failure might not occur at the highest stress interface. The probabilistic distributions of the strength based on the present assumption being expressed by maximum interlaminar tensile stress in the specimen and equivalent area calculated considering the nonuniform stress distribution became a Weibull distribution of the maximum interlaminar tensile stress. The experimental results were well agreed by the present probabilistic expression. The probabilistic expression of the interfacial strength is appropriate to assess the interfacial strength problem including volume effects and can be applied to the general interfacial failure problems with nonuniform arbitrary stress states.抄録全体を表示PDF形式でダウンロード (2841K)
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