FLUIDIZATION, CONDENSATION AND CLUSTERIZATION OF A VIBRATING COLUMN OF BEADS

Abstract

We present numerical and experimental results for the response under external vibration of one-dimensional columns of beads. Such systems are toy-models for dissipative granular materials. We show that a simple algorithm is able to reproduce the basic experimental features. Our main result is that an increase in acceleration leads to a transition from a condensed to a fluidized state of the columns. We discuss this cross-over acceleration as a function of the number of beads and of the restitution coefficient (dissipation) per collision. Also, we show that at high dissipation level clustered states (where all the beads are in contact) exist. The algorithm used by us reproduces well this cluster dynamics.