Year: 2025
Type: article
Abstract: Disordered granular packings share many similarities with supercooled liquids, particularly in the rapid increase of structural relaxation time within a narrow range of temperature or packing fraction. However, it is unclear whether the dynamics of granular materials align with those of their corresponding thermal hard sphere liquids, and the specific influence of friction in a granular system remains largely unexplored. Here, we experimentally study the slow relaxation and the steady state of monodisperse granular sphere packings under vertical tapping using X-ray tomography. We first calculate the thermodynamic parameters including the effective temperature and configurational entropy under the Edwards’ ensemble of packings of granular spheres with varying friction, and measure their characteristic relaxation time during compaction. We then present a unified picture of the relaxation process in granular systems, in which a generalized Adam-Gibbs relationship is followed. These results clarify the close relationship between granular materials and the ideal frictionless hard sphere model. Granular matter exhibit slow dynamics similar to glassy systems, but the impact of particle friction on relaxation processes remains unclear. Through experiments on tapped granular packings, the authors find that the relaxation behaviors of granular systems with varying frictional properties consistently follow a generalized law of atomic glasses, suggesting a quasi-universal mechanism shared by both systems.
Source: Communications Physics
Authors: Xinyu Ai, Houfei Yuan, Shuyang Zhang, Zhikun Zeng, Hanyu Li, Chengjie Xia, Yujie Wang
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,990
Award: G5380841065
OpenAlex ID: W4409412692