著者
上田 政人 平賀 淳人 西村 哲
出版者
The Japan Society for Composite Materials
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.37, no.3, pp.103-110, 2011 (Released:2012-02-25)
参考文献数
23
被引用文献数
4 3

Micro-buckling characteristic of a carbon mono-fiber in matrix was studied. A fiber was modeled in matrix as a column on elastic foundation. Buckling stress of the fiber was calculated incorporating the initial fiber misalignment and non-linearity of the matrix. The effect of bending on compressive stress was also taken into considered to estimate failure initiation at fiber surface. Two processes of ultimate fiber failure were considered. First one is a compressive fracture at fiber surface due to compression and bending. Second one is a matrix-yielding initiated unstable fiber deformation. Compression test of a carbon fiber in matrix was performed by means of a four point bending test. Electrical resistance of the carbon fiber was measured during the compression test to recognize initiation of the compressive fracture. Fiber breaks at two adjacent locations were observed, which was caused by micro-buckling of the fiber. Apparent compressive strength of the fiber was measured in the experiment. Actual compressive strength of the fiber was predicted from the apparent compressive strength. Correlation between compressive strengths based on the elastic foundation model and the kink band model was discussed.
著者
福田 博
出版者
一般社団法人 日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.22, no.1, pp.19-25, 1996-01-15 (Released:2009-08-11)
参考文献数
4
被引用文献数
6
著者
堤 和男
出版者
日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.2, no.3, pp.107-113, 1976-07-31 (Released:2009-08-11)
参考文献数
41
著者
岩堀 豊
出版者
日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.27, no.3, pp.173-176, 2001-05-15 (Released:2009-08-11)
参考文献数
7
著者
高坂 邵
出版者
日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.13, no.4, pp.156-162, 1987-07-15 (Released:2009-08-11)
参考文献数
1
被引用文献数
2 1
著者
干川 大和 白須 圭一 岡部 朋永
出版者
一般社団法人 日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.48, no.4, pp.142-148, 2022-07-15 (Released:2023-07-29)
参考文献数
20
被引用文献数
1

Recent years have witnessed the development of 3D printing systems of continuous carbon fiber reinforced thermoplastics (CFRTP) for use in various applications. In terms of convenience, 3D printing of CFRTP has attracted considerable attention in various fields and industries. In this study, non- and open-hole compressive (NHC and OHC) properties of 3D-printed CFRTP were evaluated. In an NHC test, the compressive elastic modulus and strength in the fiber alignment (0º) direction were obtained with values of 58.1±4.0 GPa and 368.0±33.3 MPa, respectively. A theoretical study of the relationship between compressive strength and the initial fiber misalignment angle showed that the latter was greater than that of conventional hot-pressed CFRTPs, suggesting that the fiber waviness of 3D printing has a negative effect on the longitudinal compressive strength. In an OHC test, cross-ply laminates with center holes were prepared, where the OHC strength was 165.6±1.2 MPa. Both fracture surface and X-ray CT observations showed that kink bands occurred in the 0º layer at the edge of the center hole and that extensive delamination was observed at the 0º/90º interface around the hole. These observations suggest that the voids attributed to 3D printing merged with the delamination derived from fiber buckling near the center hole, leading to rapid expansion of the delamination.
著者
川越 吉晃 小森 翔平 菊川 豪太 白須 圭一 岡部 朋永
出版者
一般社団法人 日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.48, no.4, pp.134-141, 2022-07-15 (Released:2023-07-29)
参考文献数
26

Recently, carbon-fiber-reinforced plastic (CFRP) has been increasingly used in the aerospace industry. To apply CFRP as an aircraft-grade structural material, thermosetting resin is used as a matrix to achieve high mechanical properties and environmental resistance. Additionally, the development of multifunctional CFRPs using matrix resins with functional properties, such as flame retardance, heat resistance, and vibration damping, is ongoing. In this study, molecular dynamics (MD) simulations and experiments were performed to analyze the thermomechanical properties of epoxy/cyanate resins compared with those of conventional epoxy/amine resins, to evaluate the application of this heat resistant resin as an aircraft-grade structural material. This study clarified the properties of epoxy/cyanate resins, which had no cure shrinkage, high glass transition temperature, and low thermal conductivity. These properties are attributed to the characteristic cross-linked structure of epoxy/cyanate resins, which demonstrates their potential as a structural material for next-generation aircrafts.
著者
鷹見 凌 染宮 聖人 平山 紀夫 山本 晃司 松原 成志朗 石橋 慶輝 寺田 賢二郎
出版者
一般社団法人 日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.48, no.1, pp.32-39, 2022-01-15 (Released:2023-02-10)
参考文献数
26

When analyzing the fracture behavior of unidirectional carbon fiber-reinforced polymer (CFRP), it is important to consider the interfacial strength between the reinforcing fiber and the base resin, and the strength of the base resin. Therefore, the adhesiveness of the base material and the compatibility with the sizing material and fibers are important design parameters in the development of CFRPs. However, a quantitative method for estimating the interfacial strength and the strength of the base resin has not been established. In this study, we propose a method to evaluate the interface strength of unidirectional CFRPs by creating learning data through a series of numerical material tests and by constructing a neural network that outputs the interface strength based on a homogenization method from the results of off-axis tensile tests. We adopt a general feed forward neural network whereby parameters are learned by employing a backpropagation method. The interfacial strength and the matrix resin strength is predicted and evaluated from the results of the off-axis tensile test to demonstrate the effectiveness of this system.
著者
福田 博
出版者
一般社団法人 日本複合材料学会
雑誌
日本複合材料学会誌 (ISSN:03852563)
巻号頁・発行日
vol.14, no.1, pp.20-25, 1988-01-15 (Released:2009-08-11)
参考文献数
6
被引用文献数
1