Control of crack formation using rheology of plastic fluid

2014 Fiscal Year Final Research Report

• Project/Area Number: 22340112
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Nihon University
• Principal Investigator: NAKAHARA Akio 日本大学, 理工学部, 准教授 (60297778)
• Co-Investigator(Kenkyū-buntansha): KITSUNEZAKI So 奈良女子大学, 自然科学系, 准教授 (00301284) ; OTSUKI Michio 島根大学, 総合理工学研究科(研究院), 講師 (30456751) ; OOSHIDA Takeshi 鳥取大学, 工学(系)研究科(研究院), 助教 (50294343) ; MATSUO Yousuke 日本大学, 理工学部, 研究員 (40611140)
• Research Collaborator: NAKAYAMA Hiroshi
• Project Period (FY): 2010-04-01 – 2015-03-31
• Keywords: 破壊の制御 / レオロジー / メモリー効果 / パターン形成 / コロイド

Outline of Final Research Achievements

Densely packed colloidal suspension, called paste, remembers the direction of mechanical motion, such as vibration and flow, and, if the paste is dried, its memory is visualized as the direction of crack propagation. In this project, we tried to reveal the mechanism of memory effect of paste and applied the memory effect to control crack formation.
We found that the attractive force between particles is necessary for the memory of flow. Magnetic paste remembers the direction of the magnetic field and the desiccation cracks run along the magnetic field. By applying a vertical vibration to the paste, we came to control the position of crack formation by localizing the area of horizontal vibration. Finally, we succeeded in erasing the memory of external field in paste by applying ultrasonic waves to the paste. As the paste becomes more homogeneous, irradiation of ultrasonic waves to a paste increases the breaking strength of the paste.

Free Research Field

統計物理学