Disordered jammed packings of frictionless spheres

TL;DR

This paper investigates the transition between un-jammed and jammed states in disordered frictionless sphere packings, revealing that it occurs over a range of volume fractions rather than at a single point.

Contribution

It demonstrates that the un-jammed to jammed transition spans a volume fraction range, not a single value, in disordered frictionless sphere packings.

Findings

Transition occurs over a volume fraction range from 0.636 to 0.646.

Identifies the limits as the random loose and close packing fractions.

Provides numerical construction of jammed states across the transition range.

Abstract

At low volume fraction, disordered arrangements of frictionless spheres are found in un--jammed states unable to support applied stresses, while at high volume fraction they are found in jammed states with mechanical strength. Here we show, focusing on the hard sphere zero pressure limit, that the transition between un-jammed and jammed states does not occur at a single value of the volume fraction, but in a whole volume fraction range. This result is obtained via the direct numerical construction of disordered jammed states with a volume fraction varying between two limits, $0.636$ and $0.646$. We identify these limits with the random loose packing volume fraction $\rl$ and the random close packing volume fraction $\rc$ of frictionless spheres, respectively.