1.
Phys Rev Lett
; 115(18): 188001, 2015 Oct 30.
Artigo
em Inglês
| MEDLINE
| ID: mdl-26565498
RESUMO
We have explored isotropically jammed states of semi-2D granular materials through cyclic compression. In each compression cycle, systems of either identical ellipses or bidisperse disks transition between jammed and unjammed states. We determine the evolution of the average pressure P and structure through consecutive jammed states. We observe a transition point Ï_{m} above which P persists over many cycles; below Ï_{m}, P relaxes slowly. The relaxation time scale associated with P increases with packing fraction, while the relaxation time scale for collective particle motion remains constant. The collective motion of the ellipses is hindered compared to disks because of the rotational constraints on elliptical particles.