著者

岡部 朋永 矢代 茂樹

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.75, no.751, pp.304-309, 2009

参考文献数

9

被引用文献数

1 1

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This study proposes the cohesive zone model (CZM) for fatigue damage growth in the notched CFRP cross-ply laminates. In this model, the damage growth in the fracture process of cohesive elements due to cyclic loading is represented by the conventional damage mechanics model. We preliminary investigated how this model can appropriately express the fatigue damage growth for the circular crack embedded in the isotropic solid material. This investigation demonstrated that this model could reproduce the results with the well-established fracture mechanics model plus the Paris law by tuning adjustable parameters. We then numerically investigated the damage progress in notched CFRP cross-ply laminates under tensile cyclic loading and compared the predicted damage patterns with experiments reported by Spearing et al. (Compos. Sci. Technol. 1992). The predicted damage patterns agreed with the experiment results that exhibited the extension of the multiple types of damage (i.e., splits, transverse cracks and delaminations) near the notches.

著者

仙波 浩雅 岡部 永年 山地 徹 沖田 圭介 山内 清 松本 賢哉

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.71, no.709, pp.1234-1242, 2005

被引用文献数

1

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This paper deals with the bulge process for forming the single-stage bellows of TiNi shape memory alloys, which is proposed as a new type of seismic applications, and especially considering the material's special behavior. Thin walled tubes with 20% cold work, whose composition is Ti51.0 at% Ni, were prepared. First they are appropriately heat-treated and then the rubber bulge process is introduced for the tubes under the condition of austenite phase at room temperature. Displacement control method is adapted to the process. Theoretical prediction of change in outer diameter of the tube on compression is derived, and modified taking into account the progress of the stress-induced martensite transformation on tube's surface by observing the detachment of the oxide layer of the surface. Finally theoretical relationship between compressive displacement and the outer diameter of the tube, which is the most inportant for the design of the bellows shape, is cleared.

著者

徐 章 池田 郁雄

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.59, no.557, pp.117-123, 1993

被引用文献数

1

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The destructive phenomenon of brittle and fatigue fracture is becoming extremely important in the problem of structures' safety. In this paper, to elucidate the fracture mechanism, it is tested experimentally to explicate the destructive phenomenon of the fractured section and fissure progression occurring due to thermal shock in typical brittle glass materials. Specifically, by the application of the newly developed method of applying electric resistance-vacuum evaporated thin films, it became possible to accurately measure the velocity of fissure propagation and also each block of glass and ceramics. As a result, the maximum velocity of fissure propagation for the glass was approximately 1 500-1 700 m/s and its average velocity was 650 m/s. It is also found that the velocity of fissure propagation in the glass by thermal shock under the condition of adding load by four-points bending is almost approximatrely 3 000 m/s.

著者

土肥 修 浅野 直輝

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.46, no.407, pp.826-836, 1980

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二物体の接触状態におけるおのおのの運動方程式は接触力を表面力と同様に扱う仮想仕事の原理に基づくFEMによって導かれる. さらに接触力成分を除去するため, 各運動方程式を結合することによって接触運動方程式を公式化し, この接触運動方程式を2個の等断面棒の縦衝突応力解析に適用した. 計算結果は周期的に変動するが, これらの平均値は一次元理論の結果に一致する. 本解析法は動的弾性接触問題に適用できることが認められる.

著者

東町 高雄 中沢 優

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.45, no.398, pp.1216-1226, 1979

被引用文献数

1

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羽根車のような曲面部の多い複雑な形状の構造物の応力解析を高精度かつ短時間で行えるようにするために,三次元局面要素と周期境界条件を用いた有限要素法プログラムを開発した.本プログラムをはり,円板,ターボ圧縮機光弾性モデル羽根車などに適用し,理論解,他のプログラムによる解,三次元光弾性による実験値と比較した.その結果,本プログラムの要素が高精度であり,しかも計算時間が大幅に短縮されたことがわかり,プログラムの実用性が確認された.