著者

坂上 賢一 加藤 和樹 岸部 駿之介

出版者

一般社団法人 日本機械学会

雑誌

M&M材料力学カンファレンス

巻号頁・発行日

vol.2017, 2017

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<p>Multicycle indentation test is applied to measure viscoelastic characteristic. In multicycle indentation test, indentation test is repeated at the same position on the specimen, and the mechanical characteristics are measured from on the impression. Therefore, the evaluation formula is introduced for the indentation measurement on the impression. An undeformed specimen and plastically deformed specimen of ABS resin are used. The result shows the measured creep compliance by multicycle indentation test is in good agreement with that by uniaxial tensile test. Thus, the proposed method can measure viscoelastic characteristics with high accuracy. Measured characteristics indicate that the undeformed specimen is isotropy but the plastically deformed specimen is anisotropy. This fact implies the development of anisotropy by reorientation and elongation of polymer chains during uniaxial plastic deformation.</p>

著者

坂上 賢一 石﨑 聡之 松原 良太

出版者

芝浦工業大学

雑誌

挑戦的萌芽研究

巻号頁・発行日

2014-04-01

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本研究は,市販ビデオカメラで撮影されたサッカーの試合映像から,背景除去などの基本的な画像処理とパーティクルフィルターを用いて選手・ボールを自動追跡してその位置を計測するものである.開発したシステムの精度は海外で使用されている既存のシステムと同程度の精度で計測できることが示された.また,計測された選手・ボール位置のデータから,攻撃時のボールの平均位置と相手チームの最終ラインを突破した攻撃との関係を分析し,ボール位置が相手ゴールに近いほど有効な攻撃が多くなることが示された.

著者

鈴木 新一 森田 康之 坂上 賢一

出版者

一般社団法人 日本機械学会

雑誌

日本機械学会論文集 A編 (ISSN:03875008)

巻号頁・発行日

vol.67, no.655, pp.432-439, 2001-03-25 (Released:2008-02-21)

参考文献数

24

被引用文献数

3 4

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High-speed holographic microscopy is applied to take successive microscopic photographs of a fast propagating crack at bifurcation. The crack speed is about 650 m/s. From the photographs, crack opening displacements (CODs) of the mother crack and two bifurcated branches are measured along the crack. A specimen with a notch is also made, where the notch has the bifurcated notch tip same as the bifurcated fast propagating crack. Opening displacement of the notch is measured by Moire interferometry under static loading condition. The measurement results show that the opening displacements of both the mother crack of the bifurcated fast propagating crack and the mother notch of the bifurcated notch are proportional to square root of the distance r from the crack or the notch tip. The opening displacements of the two bifurcated branches of the notch are also proportional to √(r). But the CODs of the bifurcated branches of the fast propagating crack are not always proportional to √(r).