Experimental Test of the Edwards Volume Ensemble of Tapped Granular Packings

Ye Yuan (1) , Yi Xing (1) , Jie Zheng (1) , Zhifeng Li (1) , Houfei Yuan (1) , Shuyang Zhang (1) , Zhikun Zeng (1) , Chengjie Xia (2) , Hua Tong (1, 3) , Walter Kob (4, 1) , Jie Zhang (1, 5) , Yujie Wang (1, 5)

1 Shanghai University
2 China West Normal University [Nanchong]
3 USTC - University of Science and Technology of China [Hefei]
4 L2C - Laboratoire Charles Coulomb
5 Shanghai Jiao Tong University [Shanghai]

Using x-ray tomography, we experimentally investigate granular packings subject to mechanical tapping for three types of beads with different friction coefficients. We validate the Edwards volume ensemble in these three-dimensional granular systems and establish a granular version of thermodynamic zeroth law. Within the Edwards framework, we also explicitly clarify how friction influences granular statistical mechanics by modifying the density of states, which allows us to determine the entropy as a function of packing fraction and friction. Additionally, we obtain a granular jamming phase diagram based on geometric coordination number and packing fraction.

Domaines: Mécanique statistique [cond-mat.stat-mech]; Systèmes désordonnés et réseaux de neurones [cond-mat.dis-nn]

Ye Yuan, Yi Xing, Jie Zheng, Zhifeng Li, Houfei Yuan, et al.. Experimental Test of the Edwards Volume Ensemble of Tapped Granular Packings. Physical Review Letters, 2021, 127 (1), pp.018002. ⟨10.1103/PhysRevLett.127.018002⟩. ⟨hal-03287898⟩