Tapped granular packings described as complex networks

Abstract

We characterize the structure of simulated two-dimensional granular packings using concepts from complex networks theory. The packings are generated by a simulated tapping protocol, which allows us to obtain states in mechanical equilibrium in a wide range of densities. We show that our characterization method is able to discriminate non-equivalent states that have the same density. We do this by examining differences in the topological structure of the contact network of the packings. In particular, we find that the polygons of the network are specially sensitive probes for the contact structure. Additionally, we compare the network properties obtained in two different scenarios: the tapped and a compressed system.

Keywords:

• granular media
• tapping
• force network
• contact network
• contact topology
• equilibrium states

Acknowledgments

R.A. thanks MIUR-FIRB RBFR081IUK for financial support. I.Z. and D.M. thank projects FIS2011-26675 (Spanish Government) and PIUNA (Universidad de Navarra).