Eur. Phys. J. E (2021) 44: 85
https://doi.org/10.1140/epje/s10189-021-00089-8

Regular Article - Flowing Matter

The role of friction in statistics and scaling laws of avalanches

Department of Physics, Faculty of Science, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, 603-8555, Kyoto, Japan

^a k.saitoh@cc.kyoto-su.ac.jp

Received: 31 March 2021
Accepted: 14 June 2021
Published online: 24 June 2021

Abstract

We investigate statistics and scaling laws of avalanches in two-dimensional frictional particles by numerical simulations. We find that the critical exponent for avalanche size distributions is governed by microscopic friction between the particles in contact, where the exponent is larger and closer to mean-field predictions if the friction coefficient is finite. We reveal that microscopic “slips” between frictional particles induce numerous small avalanches which increase the slope, as well as the power-law exponent, of avalanche size distributions. We also analyze statistics and scaling laws of the avalanche duration and maximum stress drop rates, and examine power spectra of stress drop rates. Our numerical results suggest that the microscopic friction is a key ingredient of mean-field descriptions and plays a crucial role in avalanches observed in real materials.