Physics (Internal)

The Influence of Topology on Sound Propagation in Granular Force Networks

This event is part of the Biophysics/Condensed Matter Seminar Series.

Abstract: Granular materials exhibit numerous rich and complex dynamics, which have been investigated from both continuum and particulate perspectives. In this talk, I will represent granular materials as spatially-embedded networks composed of nodes (particles) and weighted edges (contact forces between particles) with definite locations in Euclidean space, and I will use ideas from network science to provide insights into how sound propagates through granular materials. By performing experiments with photoelastic particles, my collaborators and I can quantitatively characterise the internal force structure, and the use of a network representation then allows one to probe its effect on sound propagation. I will discuss how network modularity, a meso-scale property, characterizes the sound propagation better than either system-scale or local-scale network features. I will also demonstrate that geographic community structure of the (weighted) granular force chain network provides a fundamental constraint on sound propagation. This work, which is available at http://arxiv.org/abs/1110.1858, is joint work with Dani Bassett, Eli Owens, and Karen Daniels.