巻号一覧
43 巻, 1 号
選択された号の論文の5件中1～5を表示しています
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研究論文
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小林 和幸, 小山 孝生, 杉村 亜寿美, 荒井 政大, 島村 佳伸2017 年 43 巻 1 号 p. 2-8
発行日: 2017年
公開日: 2018/03/15
ジャーナル フリーThis study proposes a prediction method for modal damping ratios of a polymer-based composite structure with a complex microscopic structure by using finite element analysis. If the modal damping ratios are given in a linear vibration problem of solid, the frequency dependence of damping characteristic can be numerically analyzed by using a mode superposition method. However, it is difficult to calculate the exact modal damping ratios by theoretical means. Therefore we proposed a method to identify the damping ratios by using numerical analysis based on a mathematical homogenization method. Given that dynamic viscoelasticity of matrix type resin is measured in advance, the proposed method enables us to calculate the modal damping ratios of a composite material with a periodic microstructure. In order to verify the validity of this method, a numerical analysis and a vibration experiment of a CFRP rectangle plate was conducted. Calculated natural frequencies, modal shapes and modal damping ratios well agreed with measured, and thus the validity of this analysis method was confirmed in CFRP.抄録全体を表示PDF形式でダウンロード (4503K) -
ルハガワスレン ウーガンスレン, 小沢 喜仁, 菊地 時雄2017 年 43 巻 1 号 p. 9-17
発行日: 2017年
公開日: 2018/03/15
ジャーナル フリーOver previous years, an increasing effort has been devoted to the use of nano particles and cellulose obtained from natural resources as reinforcing elements for the composites with polymeric matrices. Bacterial cellulose (BC) can be also used in composite materials, usually combined with both organic and inorganic particles. We have already developed the nano-C/C composites using BC and phenol resin, and wear and friction properties have been investigated. In this study, fabrication method of the BC/BP composites with bamboo charcoal particle (BP) as Si additive, and mass fraction effect of BP on the wear and friction properties were investigated. The dry sliding wear test for the composites had been carried out against the SUS304 counter face by using a pin-on-drum type tribological apparatus. From the wear test results, the wear and friction properties of the BC/BP composites were dependent on BP mass fraction and carbonizing temperature. The friction coefficients had low values of 0.15∼0.30, and the specific factors of wear element loss were 2.16×10−10∼1.12×10−9 mm2/N. The experimental results indicated that BP can be applied as filler which can provide lower wear and friction properties.抄録全体を表示PDF形式でダウンロード (7108K) -
菅沼 啓史, 山下 慎一郎, 大澤 勇, 髙橋 淳2017 年 43 巻 1 号 p. 18-24
発行日: 2017年
公開日: 2018/03/15
ジャーナル フリーWe used ultra-thin chopped carbon fiber tape reinforced thermoplastics (UT-CTT) which is randomly oriented strands (ROS) made of ultra-thin carbon fiber thermoplastic prepreg by using paper making technique. UT-CTT was developed for the weight reduction of mass-production vehicles and shows as high mechanical properties as those of thermosetting CFRP (carbon fiber reinforced plastics) for airplane structures. Concerning the moduli and their variance of ROS, a theoretical methodology to predict them was proposed by Zhang, but verification of this methodology in the actual material has not been performed yet. Hence, in this study, the applicable range of the methodology is experimentally verified using statistical hypothesis test and the potential of this prediction methodology is investigated. As a result, it can be concluded that Zhang’s model is useful within the actual application although there are some differences between the theoretical assumption and the actual material when the material is too thin because of the distortion of fibers and some gaps attributed to the edge of chopped tapes. Additionally, the specimen size of ROS is generally large because of its large scatter, but it was shown that of UT-CTT is relatively small because of its thinness of chopped tapes.抄録全体を表示PDF形式でダウンロード (4881K) -
小熊 広之, 坂本 大輔, 原田 雅典, 関根 正裕, 平山 紀夫, 邉 吾一2017 年 43 巻 1 号 p. 25-32
発行日: 2017年
公開日: 2018/03/15
ジャーナル フリーThe purpose of this study is to improve the mechanical properties of carbon fiber reinforced thermoplastics (CFRTP) using polyamide6 (PA6) as a matrix resin. To achieve this purpose, we investigated the surface modification method for both carbon fiber fabrics (CFFs) and PA6 films. In order to improve the adhesion between CFFs and PA6 films, ozone oxidation treatment was adopted. This treatment was carried out for both CFFs and PA6 films. In comparison with the untreated sample, it was found that flexural strength and tensile strength increased 106% and 44%, respectively. This would be because the oxygen-containing functional groups were generated on both surfaces of CFFs and PA6 films by the effect of the ozone oxidation treatment, it was assumed that the adhesion of the interface was improved.抄録全体を表示PDF形式でダウンロード (6091K) -
佐藤 光桜, 今井 えりな, 小柳 潤, 石田 雄一, 小笠原 俊夫2017 年 43 巻 1 号 p. 33-39
発行日: 2017年
公開日: 2018/03/15
ジャーナル フリーThis paper presents an evaluation method for the fiber/matrix interfacial strength. The interfacial strength is determined by comparing experimental data with numerical simulations. The micro-droplet test is conducted, and the fiber axial stress at the point of interface debonding is obtained. A numerical simulation is performed with ABAQUS using an axisymmetric finite element model. In the numerical simulation, an accurate value of the thermal residual stress based on the thermo-viscoelasticity and the damage to the resin around the blade-contacting point are considered to simulate the experimental phenomena ideally. In the thermal residual stress analysis, the actual thermal residual stress is calculated by considering the relaxation modulus and the time-temperature superposition principle for the resin. Damage initiation criteria for both dilatational and shear cases, based on continuum damage mechanics, is considered for the resin. Interfacial debonding is simulated by using a cohesive zone model, and the interfacial strength is determined as strength of the cohesive zone element when the fiber maximum stress by simulation corresponds to the experiments.抄録全体を表示PDF形式でダウンロード (4273K)
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