Propagating front in an excited granular layer
Abstract
A partial monolayer of ~ 20000 uniform spherical steel beads, vibrated vertically on a flat plate, shows remarkable ordering transitions and cooperative behavior just below 1g maximum acceleration. We study the stability of a quiescent disordered or ``amorphous'' state formed when the acceleration is switched off in the excited ``gaseous'' state. The transition from the amorphous state back to the gaseous state upon increasing the plate's acceleration is generally subcritical: An external perturbation applied to one bead initiates a propagating front that produces a rapid transition. We measure the front velocity as a function of the applied acceleration. This phenomenon is explained by a model based on a single vibrated particle with multiple attractors that is perturbed by collisions. A simulation shows that a sufficiently high rate of interparticle collisions can prevent trapping in the attractor corresponding to the nonmoving ground state.
Cite
@article{arxiv.cond-mat/9812089,
title = {Propagating front in an excited granular layer},
author = {W. Losert and D. G. W. Cooper and J. P. Gollub},
journal= {arXiv preprint arXiv:cond-mat/9812089},
year = {2009}
}
Comments
16 pages, 9 figures, revised version, to appear in Phys. Rev. E, May 1999