Topological Complexity of Frictional Interfaces: Friction Networks

TL;DR

This study introduces a network-based approach to analyze frictional interfaces, revealing universal power laws, energy localization differences, and correlations with fluid flow, advancing understanding of fracture permeability and rupture dynamics.

Contribution

It develops a novel network methodology to characterize frictional interfaces and uncovers universal patterns and energy behaviors not previously documented.

Findings

Universal power law between node degree and motif frequency.

Higher energy radiation rate in parallel friction networks.

Correlation between sub-graph distribution and fluid flow.

Abstract

Through research conducted in this study, a network approach to the correlation patterns of void spaces in rough fractures (crack type II) was developed. We characterized friction networks with several networks characteristics. The correlation among network properties with the fracture permeability is the result of friction networks. The revealed hubs in the complex aperture networks confirmed the importance of highly correlated groups to conduct the highlighted features of the dynamical aperture field. We found that there is a universal power law between the nodes' degree and motifs frequency (for triangles it reads T(k)\proptok{\beta} ({\beta} \approx2\pm0.3)). The investigation of localization effects on eigenvectors shows a remarkable difference in parallel and perpendicular aperture patches. Furthermore, we estimate the rate of stored energy in asperities so that we found that the rate of radiated energy is higher in parallel friction networks than it is in transverse directions. The final part of our research highlights 4 point sub-graph distribution and its correlation with fluid flow. For shear rupture, we observed a similar trend in sub-graph distribution, resulting from parallel and transversal aperture profiles (a superfamily phenomenon).