'Flow & Jam' of frictional athermal systems under shear stress

TL;DR

This study uses molecular dynamics simulations to explore how frictional athermal particles transition from flowing to jammed states under shear stress, revealing critical behaviors and correlations in the process.

Contribution

It provides new insights into the jamming transition by analyzing the divergence of jamming times and contact correlations in frictional athermal systems.

Findings

Jamming time diverges as volume fraction decreases.

Jamming time distribution follows a power-law near criticality.

Flowing regime shows a correlation between shear velocity and contact number Z.

Abstract

We report recent results of molecular dynamics simulations of frictional athermal particles at constant volume fraction and constant applied shear stress, focusing on a range of control parameters where the system first flows, but then jams after a time tjam. On decreasing the volume fraction, the mean jamming time diverges, while its sample fluctuations become so large that the jamming time probability distribution P(tjam) becomes a power-law. We obtain an insight on the origin of this phenomenology focusing on the flowing regime, which is characterized by the presence of a clear correlation between the shear velocity and the mean number of contacts per particles Z, whereby small velocities occur when Z acquires higher values.