Effects of friction on jamming transition

2022 Fiscal Year Final Research Report

• Project/Area Number: 21K20355
• Research Category: Grant-in-Aid for Research Activity Start-up
• Allocation Type: Multi-year Fund
• Review Section: 0202:Condensed matter physics, plasma science, nuclear engineering, earth resources engineering, energy engineering, and related fields
• Research Institution: Gakushuin University
• Principal Investigator: Ikeda Harukuni 学習院大学, 理学部, 助教 (30911763)
• Project Period (FY): 2021-08-30 – 2023-03-31
• Keywords: 非平衡 / 相転移 / 粉体 / ジャミング転移 / レプリカ法

Outline of Final Research Achievements

A collection of macro particles, such as sands, grains, M&M candies, and so on, is referred to as a granular material. When a granular material is compressed, at a certain density, it suddenly begins to exhibit finite rigidity and behaves like a solid. This is the so-called jamming transition. The jamming transition is a universal phenomenon observed when granular systems are compressed, and it has been attracting a lot of attention as a representative example of phase transitions in non-equilibrium systems consisting of macroscopic particles. Near the jamming transition point, several physical quantities, such as pressure and stiffness, show power-law behavior, and at the transition point, correlation lengths and relaxation times diverge. In this work, we performed numerical simulation and mean-field calculations to deepen our understanding of these critical aspects of the jamming transition.

Free Research Field

粉体物理学

Academic Significance and Societal Importance of the Research Achievements

砂や、穀物を始めとして、我々の身の回りには、数多くの粉体が存在する。ジャミング転移は、この粉体を圧縮していった際に見られる普遍的な現象であり、粉体の粘弾性を理解する上で重要な役割を果たすことが期待される。また、粉体の流動化という点において、ジャミング転移は、雪崩や地震等とも類似した現象であり、これらの現象を理解する礎になる可能性がある。