Stick-slip transition in the Scalar Arching Model

Abstract

When some granular material contained into a silo is pushed upwards with a piston, an irregular stick-slip motion of the system of grains is observed. We show how one can adapt the Scalar Arching Model (SAM) -- proposed as a model for giant stress fluctuations in silos -- in order to describe this stick-slip phenomenon. As a function of the sensitivity of the system to mechanical noise, the system exhibit two different phases: a jammed phase, and a sliding phase where irregular stick-slip is observed. We analyze the transition, which is found to be of mean-field type, and study the statistical properties of the intermittent stick-slip motion.