鐙 優太, 池田 徹, 小金丸 正明 . 分子静力学法および結合力モデルを用いた異種材接合角部のき裂等価臨界応力拡大係数の推定 . 日本機械学会論文集87 ( 899 ) 21 - 00119-21-00119 2021年7月 詳細を見る 記2021 · 記述言語: 日本語 掲載種別: 研究論文(学術雑誌) 出版者・発行元: 一般社団法人 日本機械学会 <p>The stress intensity factors (SIFs) for an interfacial corner, which are compatible with that for a crack, can describe the singular stress field around the corner. However, due to the difference of the singular order with the angle of a corner and the combination of materials, we cannot compare the SIFs of interfacial corners to that with different singular orders. In this study, we estimated the fracture toughness (critical SIF) of jointed interfacial corners with different opening angles and different combinations of materials using the molecular statics method and cohesive zone model. The critical SIFs were normalized using those of interfacial cracks with the same combinations of materials. Regarding the relationships between the normalized critical SIF and the singular order for the numerical experiments using both the molecular statics method and cohesive zone model, the normalized SIF increased exponentially with decreasing singular order. The relationship between the singular order and the critical SIF obtained by the molecular statics or the cohesive model was almost unique regardless of the combination of materials and jointed angles. In other words, it is possible to translate the critical SIFs of a jointed interfacial corner to that of interfacial crack. However, the slopes of the relationship obtained by the molecular statics and the cohesive zone model did not correspond. This might be because only the molecular statics method considers the influence of crystal structure factors such as slip and dislocation. The interactions between atoms of the molecular statics and cohesive zone model along the interfaces are different. The relationship between the singular order and the critical SIF of actual jointed interfacial corner must be investigated experimentally in further research.</p> DOI: 10.1299/transjsme.21-00119 CiNii Research
鐙 優太, 木之瀬 優孝, 古賀 裕二, 池田 徹, 小金丸 正明 . 熱応力下における3次元異方性異種材接合角部の特異応力場解析 . 材料70 ( 5 ) 412 - 419 2021年5月 詳細を見る 記述言語: 日本語 掲載種別: 研究2021 · 記述言語: 日本語 掲載種別: 研究論文(学術雑誌) 出版者・発行元: 公益社団法人 日本材料学会 <p>In our previous study, we proposed a new technique to analyze the asymptotic solution of the singular stress field around a three-dimensional interfacial corners under mechanical stress. We analyzed the scalar parameters of the asymptotic solutions using the <i>H</i>-integral, which is a conservation integral, in conjunction with the finite element analysis. In this study, we extended the previous study to the three-dimensional interfacial corners under thermal stress. Thermal stress is the main cause of the fracture from an interfacial corner between dissimilar materials. We also normalized the scalar parameters that is compatible with the scalar parameters obtained by two-dimensional <i>H</i>-integral using the Stroh formalism. We demonstrate that the obtained eigen vectors and scalar parameters are correspond with that obtained by the two-dimensional method. We have also shown an example of perfect three-dimensional corners under thermal stress. Obtained asymptotic solution reasonably approximated the stress field around the corner.</p> DOI: 10.2472/jsms.70.412 CiNii Research