Statistical physics on structure and dynamics of microcracks in thermally activated breakdown of heterogeneous materials

• Project/Area Number: 17K14360
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Institute of Physical and Chemical Research
• Principal Investigator: Yoshioka Naoki 国立研究開発法人理化学研究所, 計算科学研究センター, 研究員 (10548209)
• Project Period (FY): 2017-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000); Fiscal Year 2020: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2018: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2017: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
• Keywords: 破壊現象 / 非平衡物理学 / 計算統計物理学 / 統計物理 / 計算物理 / 粉体物理 / 統計物理学 / 破壊 / 統計力学 / 機械材料・材料力学 / 自然現象観測・予測

Outline of Final Research Achievements

We study thermally activated creep fracture of heterogeneous materials by using so-called thermally activated fiber-bundle models. In this study, in order to characterize change of fracture process due to stress concentration, we concentrate on correlation integral and jump distance distribution of epicenters. The results about correlation integral suggests fractal structures of microcracks appear in the vicinity of catastrophic breakdown. Meanwhile, we find nontrivial power-law distributions of jump distance of epicenters.

Academic Significance and Societal Importance of the Research Achievements

本研究の結果は、破壊過程が進むことで応力集中が発生した際、微小破壊の構造を特徴づける量に着目すると、自明な状態から非自明な状態に変化する様子が観測できることを示している。系のパラメタによるところはあるが、この成果は材料の破断を、微小亀裂の発生地点に関する統計量から予測する可能性を示唆している。

Research Products

• [Int'l Joint Research] デブレツェン大学(ハンガリー)
• [Int'l Joint Research] デブレツェン大学(ハンガリー)
• [Int'l Joint Research] デブレツェン大学(ハンガリー)
• [Int'l Joint Research] デブレツェン大学理論物理学科(ハンガリー)
• [Presentation] 熱活性破壊における微小亀裂間距離に関する統計分布 (2020)
  • Author(s): 吉岡直樹
  • Organizer: 日本物理学会2020年秋季大会
• [Presentation] Jump distance distributions of epicenters in thermally induced cracking of fiber bundles (2019)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: Naha Workshop on Fracture Dynamics and Structure of Cracks
  • Int'l Joint Research
• [Presentation] 熱活性破壊における微小亀裂発生点の統計分布 (2018)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: 日本物理学会2018年秋季大会
• [Presentation] Epicenter jump and burst size in thermally induced cracking of fiber bundles (2018)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: 9th Hungary-Japan Bilateral Workshop on Statistical Physics of Breakdown Phenomena
  • Int'l Joint Research
• [Presentation] Jump statistics of epicenters in thermally induced cracking of fiber bundles (2018)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: MMM2018, The 9th International Conference on Multiscale materials Modeling
  • Int'l Joint Research
• [Presentation] Jump distance of epicenters in thermally induced cracking (2018)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: Fukui Workshop on Fracture dynamics and Structure of Cracks
  • Int'l Joint Research
• [Presentation] Kinetic Monte Carlo algorithm for thermally induced breakdown of fiber bundles (2017)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: The 4th International Workshop on Physics of Social Compexity
  • Int'l Joint Research
• [Presentation] 熱活性破壊のファイバーバンドル模型における亀裂生成の空間分布 (2017)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: 日本物理学会２０１７年秋季大会
• [Presentation] Jump distance of epicenters in thermally induced cracking (2017)
  • Author(s): 吉岡直樹、フェレンツ・クン、伊藤伸泰
  • Organizer: 8th Hungary-Japan bilateral Workshop on Statistical Physics of Breaking Phenomena
  • Int'l Joint Research