Rheology of cohesive granular particles under constant pressure

TL;DR

This study investigates how cohesive granular materials behave under constant pressure, revealing four distinct flow phases and how cohesion influences friction and force anisotropies through molecular dynamics simulations.

Contribution

It identifies four rheological phases in cohesive granular systems and explains the influence of cohesion on friction and force anisotropy, including the role of second-nearest neighbors.

Findings

Four distinct flow phases identified: uniform shear, oscillation, shear-banding, clustering.

Friction coefficient increases with inertial number and cohesion strength.

Second-nearest neighbors significantly affect rheological behavior.

Abstract

The rheology of cohesive granular materials, under a constant pressure condition, is studied using molecular dynamics simulations. Depending on the shear rate, pressure, and interparticle cohesiveness, the system exhibits four distinctive phases: uniform shear, oscillation, shear-banding, and clustering. The friction coefficient is found to increase with the inertial number, irrespective of the cohesiveness. The friction coefficient becomes larger for strong cohesion. This trend is explained by the anisotropies of the coordination number and angular distribution of the interparticle forces. In particular, we demonstrate that the second-nearest neighbors play a role in the rheology of cohesive systems.