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2022/4 Vol.125

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論文アクセスランキング

論文アクセスランキング 日本機械学会学術誌(和文) 年間アクセス数トップ10

(2021年1月~2021年12月の期間で集計)


温度と湿度による樹脂材料の強度低下の予測

澤田 祐子, 越前谷 大介

日本機械学会論文集(2019) DOI:10.1299/transjsme.18-00505

A large quantity of engineering plastics are used in electric industrial products. It is necessary to estimate the life of the product made of engineering plastics because of its shorter life and lower strength than some of ceramics or metals. Polybutylene terephthalate is one of the hydrolyzed engineering plastics. Their test pieces were submitted to accelerated stress test of elevated temperature and humidity. Their strength was evaluated by three-point bending test. It was found that the strength degradation was related to water vapor pressure, temperature and retention time. It was possible to estimate the time required for strength degradation in service environment.


内燃機関自動車,ハイブリッド自動車,電気自動車,燃料電池自動車における車内空調を考慮した量産車両LCCO2排出量の比較分析

石崎 啓太, 中野 冠

日本機械学会論文集 (2018) DOI:10.1299/transjsme.18-00050

This study systematically analyzed life cycle CO<sub>2</sub> (LCCO<sub>2</sub>) emissions of a comprehensive set of mass-produced 2,000 cc class sedan-type vehicles, using a hybrid life cycle inventory approach. Gasoline and diesel internal combustion engine vehicles (ICEVs), hybrid electric vehicle (HEV) as well as battery electric vehicle (BEV) and fuel cell vehicle (FCV) were investigated, considering (i) the current BEV market trends, (ii) Japan’s energy mix (the average for 2012–2014), and (iii) the use of the HVAC system. The results show that the annual average increment of CO<sub>2 </sub>emissions in use phase by HVAC system in Japan (assumed annual mean temperature of 15°C) was presumed to be evenly 9% regardless of vehicle types, although further detail analysis is required. The CO<sub>2</sub> emissions in use phase of BEV were higher than those of HEV and FCV (applied hydrogen produced by steam reforming of LPG (on-site)) due to thermal power dominant electricity generation mix in Japan in recent years. As a consequence of high CO<sub>2</sub> emissions from power supply and battery production, the LCCO<sub>2</sub> emissions of BEV equipped with 75 kWh battery were higher than those of HEV, FCV (on-site), and conventional ICEV (diesel). By reducing the battery capacity to 40 kWh or less, the LCCO<sub>2</sub> emissions of BEV become lower than those of ICEVs and FCV (on-site), making BEV a competitive alternative. However, it is difficult that BEV mitigates both LCCO<sub>2</sub> emissions and driver’s range anxiety. In conclusion, HEV shows the competitive performance in terms of LCCO<sub>2</sub> emissions with long driving range in Japan.


部分撥水処理を施した平坦なスラスト軸受の超音波膜厚測定

竹内 彰敏

日本機械学会論文集C編 (2013) DOI:10.1299/kikaic.79.2164

A flat thrust bearing, that has a structure which generates a pressure flow by using the discontinuity of shear flow rate between a water-repellent surface and a hydrophilic surface, was developed. In this study, ultrasonic pulse echo technique was employed for the investigation of the film thickness influenced by the static contact angle θ (≅10°, 60°, 110°) and the water-repellent area ratio β(=0.25, 0.5, 0.75). Since the occurrence of the slip of water at a water-repellent surface having 110° of static contact angle is easy, observed lubrication film thickness is thicker than that of θ≅60°, and the film thickness at θ≅10° becomes thinnest. The film thickness is different by the area ratio β of water-repellent region against a bearing surface area, and it thickens in order of β=0.25, 0.75, 0.5. Thickest film is formed around of the β where the area of water-repellent region is equal to hydrophilic area. Calculation results of the infinite long bearing approximation, which considered the slip on a wall, agree with the characteristics of measured film thickness mentioned above. Therefore this thrust bearing operates under similar mechanism with conventional bearing having lubrication surfaces which shapes a wedge film. The order of measured film thickness agrees with order of satisfactory bearing of friction characteristics in each bearing tested. Consequently it can be conclude that the main factor of which coefficient of friction under a same load and speed is different by static contact angle θ and water-repellent area ratio β is a variance of film thickness in each bearing.


4位

ガウス過程回帰を用いたブラジャーカップの形状設計支援

吉田 皓太郎, 若松 栄史, 岩田 剛治, 久保 貴裕
日本機械学会論文集 (2021) DOI:10.1299/transjsme.21-00201

5位

粒子法における時間進行法の改良

松永 拓也, 越塚 誠一
日本機械学会論文集 (2021) DOI:10.1299/transjsme.20-00437

6位

電子ビーム積層造形で作製したTiAl4822合金の機械的特性へ及ぼすHIP処理の影響

水田 和裕, 井上 佳奈, 後閑 一洋, 筧 幸次
日本機械学会論文集 (2021) DOI:10.1299/transjsme.20-00330

7位

ヘルツ接触理論の高速収束計算手法

大場 一輝
日本機械学会論文集 (2014) DOI:10.1299/transjsme.2014cm0105

8位

エレベータ用ワイヤロープの径方向剛性を再現する有限要素モデリング

泉 聡志, 中谷 起也, 太田 仁衣奈, 波田野 明日可, 山際 謙太
日本機械学会論文集 (2021) DOI:10.1299/transjsme.20-00418

9位

トンネル走行時の鉄道車両動揺に関わる変動空気力の発生メカニズム(単純形状の鉄道車両モデルにおける大規模流れ構造のLES)

中出 孝次, 佐久間 豊, 梶島 岳夫
日本機械学会論文集 (2021) DOI:10.1299/transjsme.20-00366

10位

機械学習を用いたしゅう動面状態監視システムに関する研究

橋本 優花, 本田 知己, 持田 裕介, 杉山 和彦, 中村 由美子, 高東 智佳子
日本機械学会論文集 (2018) DOI:10.1299/transjsme.18-00275

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