Predicting Defects in Soft Sphere Packings Near Jamming Using The Force Network Ensemble

TL;DR

This paper introduces a method to identify defect contacts in amorphous soft particle systems near jamming by analyzing the force network ensemble, enabling accurate defect detection and understanding of system stability.

Contribution

It presents a novel approach to detect non-essential contacts in force networks near jamming by examining the boundaries of the force network ensemble.

Findings

Defect contacts can be uniquely identified near jamming.

Defect contacts break under decompression.

The method is highly accurate close to the jamming transition.

Abstract

Amorphous systems of soft particles above jamming have more contacts than are needed to achieve mechanical equilibrium. The force network of a granular system with a fixed contact network is thus underdetermined, and can be characterized as a random instantiation within the space of the force network ensemble. In this work, we show that by examining the boundaries of this space of allowed force networks, defect contacts which are not necessary for stability of the system can be uniquely identified. We further show that in the near jamming limit, this identification is nearly always correct and the defect contacts are broken under decompression of the system.