Elastic behavior in Contact Dynamics of rigid particles

TL;DR

This paper investigates the elastic effects introduced by the Contact Dynamics simulation method for dense granular media, highlighting how iterative solvers induce effective elasticity and sound propagation, and compares these effects with soft particle molecular dynamics.

Contribution

It provides an analytical and numerical analysis of the elastic phenomena in Contact Dynamics, clarifying the method's limitations and differences from soft particle approaches.

Findings

Effective elasticity arises from iterative solver implementation.

Sound propagation occurs with finite velocity in simulations.

Limits of Contact Dynamics applicability are characterized.

Abstract

The systematic errors due to the practical implementation of the Contact Dynamics method for simulation of dense granular media are examined. It is shown that, using the usual iterative solver to simulate a chain of rigid particles, effective elasticity and sound propagation with a finite velocity occur. The characteristics of these phenomena are investigated analytically and numerically in order to assess the limits of applicability of this simulation method and to compare it with soft particle molecular dynamics.