Research on Internal Structures Responsible for the Fracture Properties of Wet Granular Materials

2016 Fiscal Year Final Research Report

• Project/Area Number: 26400395
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Mathematical physics/Fundamental condensed matter physics
• Research Institution: Nara Women's University
• Principal Investigator: Kitsunezaki So 奈良女子大学, 自然科学系, 准教授 (00301284)
• Co-Investigator(Renkei-kenkyūsha): MIZUGUCHI Tsuyoshi 大阪府立大学, 工学研究科, 准教授 (80273431) ; OTSUKI Michio 島根大学, 総合理工学研究科, 講師 (30456751)
• Research Collaborator: NISHIMOTO Akihiro 関西大学, 人間健康学部, 非常勤講師
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 物性基礎論 / 非線形動力学 / レオロジー / 乾燥破壊 / 揺れの記憶効果 / 応力異方性 / X線CT / 石松子ペースト

Outline of Final Research Achievements

When paste-like mixtures of fine solid particles and liquid are shaken horizontally and left undisturbed, lines of desiccation cracks perpendicular to the direction appear after drying. We investigated wet granular materials (pastes) with such memory of shaking. We developed the method of stress measurements by using plate springs and found that stress anisotropy increases as drying proceeds in calcium carbonate pastes. We next confirmed that two types of pastes of large granules, starch and Lycopodium powder, exhibit the memory effect of shaking, and found statistical anisotropies in the microscopic arrangements of Lycopodium particles by using micro focus X-ray CT, which are consistent with macroscopic anisotropy in stresses. These are the first results which indicate the existence of anisotropic structures before the formation of desiccation cracks and important information to clarify the memory effect.

Free Research Field

非線形動力学