巻号一覧
39 巻 (2013)
- 6 号 p. 212-
- 5 号 p. 167-
- 4 号 p. 127-
- 3 号 p. 89-
- 2 号 p. 49-
- 1 号 p. 10-
39 巻, 2 号
選択された号の論文の4件中1～4を表示しています
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研究論文
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渡辺 知規, 胡 寧, 井上 創, 滝澤 直弥, 李 淵2013 年 39 巻 2 号 p. 49-56
発行日: 2013年
公開日: 2014/03/31
ジャーナル フリーMulti-walled carbon nanotube (MWNT)/epoxy resin composites have been fabricated by combining with the three different conditions, namely surface acid-treatment on MWNT, cure under pressure and liquid rubber modification. In order to investigate the effects of those three conditions on the mechanical properties of MWNT/Epoxy composite with different weight percentages of MWNTs, the tensile test and the three-point bending test have been carried out. The fracture surfaces have been observed by using scanning electron microscope (SEM). As a result, it is shown that since the surface acid-treatment is effective in improving the dispersion of MWNT in polymer and the interfacial bonding properties between MWNT and polymer matrix, the surface acid-treatment is useful to increase the maximum tensile stress and the critical strain energy release rate. The cure under pressure has a positive effect to reduce the number of voids in the composite, which have the decisive role in the fracture behavior. The liquid rubber modification increases the failure strain with declining the maximum tensile stress. Moreover, since the liquid rubber modification is effective to improve the reinforcement capability of MWNT, the liquid rubber modification markedly increases the critical strain energy release rate.抄録全体を表示PDF形式でダウンロード (1907K) -
山地 周作, 小林 訓史2013 年 39 巻 2 号 p. 57-64
発行日: 2013年
公開日: 2014/03/31
ジャーナル フリーBioactive ceramics/poly-L-lactic acid (PLLA) composites have been expected as a material for the bone fracture fixations which have more biocompatibility than monolithic PLLA. In this study, monolithic PLLA and β-tricalcium phosphate (β-TCP)/PLLA composites containing three different β-TCP contents (5, 10, 15 wt%) were prepared by injection molding and hydrolysis behavior in simulated body environment were characterized. These specimens were immersed in phosphate buffered solution, and water absorption and molecular weight weremeasured. Water absorption of monolithic PLLA increased with increasing immersion time up to 14days, and then saturated, whereas water absorption of composites increased with increasing immersion timeup to 168 days. The composites with higher β-TCP contents showed larger water absorption. Number averaged molecular weight degradation of composites became faster for higher β-TCP content at the same immersion time. Number averaged molecular weight of 15 wt% composites decreased from 60,000 to 39,000 after 24 weeks immersion. Two layers model and three layers model were proposed to predict water absorption and number average molecular weight variation, respectively. To predict hydrolysis behavior of bioactive ceramics/PLLA composites more precisely, effect of water diffusion is considered in proposed models. Predictions based on the present models are in good agreement with experimental results and the effectiveness of the models was confirmed.抄録全体を表示PDF形式でダウンロード (1543K) -
中村 俊一郎, 松原 監壯, 高雄 善裕, 汪 文学2013 年 39 巻 2 号 p. 65-71
発行日: 2013年
公開日: 2014/03/31
ジャーナル フリーComposite materials, especially carbon fiber reinforced plastics (CFRP), have been widely used in the airplane primary structures like wing or fuselage panel. An airplane damaged in service by accident or serious incident is repaired by removing the damaged area and by bonding or fastening a patch. The total cost of repair is expected to decrease by the combination of the time-limited and permanent repair. Thus, it is important to grasp the strength characteristics on a small patch for the time-limited repair and a large patch for the permanent repair. In this paper a fuselage panel made of thin CFRP laminates and a specimen repaired by bonding a CFRP patch to the panel with a rectangular hole were tensile tested. The broken specimens were observed precisely in detail by both a magnifying glass and an optical microscope, which leads to the result that different sizes of patch have different initial failure points. That is, time-limited and permanent patches have the cohesive failure at central and side patch ends, respectively.抄録全体を表示PDF形式でダウンロード (2189K) -
鮑 力民, 銭 丹娜, 山元 剛, 山中 敦彦, 剱持 潔2013 年 39 巻 2 号 p. 72-77
発行日: 2013年
公開日: 2014/03/31
ジャーナル フリーThe erosion resistance of fiber reinforced plastic (FRP) composites becomes to be significant while FRP materials are applied in erosive environments. It is demanded to improve erosion resistance of the FRP with high strength. The erosion resistance of the FRP used high strength polyethylene fiber (DF) is better but more expensive than carbon fiber (CF). To realize high cost performance FRP, in this study, the hybrid structure FRP was developed by the use of high strength polyethylene fiber for outside lamina and CF for inner layers. The erosion behavior and bending properties of DF/CF-hybrid FRP were compared with CFRP and GFRP. The results confirmed that DF/CF-hybrid composites exhibited high strength and superior particle erosion resistance. The decrease of mechanical strength after a erosion of the hybrid FRP was smaller than CFRP.抄録全体を表示PDF形式でダウンロード (1551K)
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