EPL (Europhysics Letters)

DOI: 10.1209/epl/i2000-00392-7

Europhys. Lett., 51 (6), p. 679 (2000)

Dynamics of vibrated granular monolayers

X. Nie ¹ - E. Ben-Naim ¹ - S. Y. Chen ^1,2

¹ Theoretical Division and Center for Nonlinear Studies
Los Alamos National Laboratory - Los Alamos, NM 87545, USA
² IBM Research Division, T. J. Watson Research Center
P.O. Box 218, Yorktown Heights, NY 10598, USA

(Received 10 November 1999; accepted in final form 5 April 2000)

PACS :
81.05.Rm - Porous materials; granular materials
05.70.Fh - Phase transitions: general studies
02.70.Ns - Molecular dynamics and particle methods

Abstract:

We study statistical properties of vibrated granular monolayers using molecular dynamics simulations. We show that at high excitation strengths, the system is in a gas state, particle motion is isotropic, and the velocity distributions are Gaussian. As the vibration strength is lowered, the system's dimensionality is effectively reduced from three to two. Below a critical excitation strength, a cluster phase occurs, and the velocity distribution becomes bimodal. In this phase, the system consists of clusters of immobile particles arranged in close-packed hexagonal arrays, and gas particles whose energy equals the first excited state of an isolated particle on a vibrated plate.

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