Network-Configurations of Dynamic Friction Patterns

TL;DR

This paper models dynamic friction patterns as networks to analyze their structure and dynamics, revealing universal scaling laws and proposing a new network-based friction law that enhances understanding of shear ruptures.

Contribution

It introduces a novel network-based approach to analyze static friction dynamics, uncovering universal scaling laws and proposing a new friction law based on network parameters.

Findings

Networks capture crack-like shear ruptures and acoustic features.

A universal power law relates node degree to motif frequency.

Network analysis reveals universal energy flow patterns in shear ruptures.

Abstract

The complex configurations of dynamic friction patterns-regarding real time contact areas- are transformed into appropriate networks. With this transformation of a system to network space, many properties can be inferred about the structure and dynamics of the system. Here, we analyze the dynamics of static friction, i.e. nucleation processes, with respect to "friction networks". We show that networks can successfully capture the crack-like shear ruptures and possible corresponding acoustic features. We found that the fraction of triangles remarkably scales with the detachment fronts. There is a universal power law between nodes' degree and motifs frequency (for triangles, it reads T(k)\proptok{\beta} ({\beta} \approx2\pm0.4)). We confirmed the obtained universality in aperture-based friction networks. Based on the achieved results, we extracted a possible friction law in terms of network parameters and compared it with the rate and state friction laws. In particular, the evolutions of loops are scaled with power law, indicating the aggregation of cycles around hub nodes. Also, the transition to slow rupture is scaled with the fast variation of local heterogeneity. Furthermore, the motif distributions and modularity space of networks -in terms of withinmodule degree and participation coefficient-show non-uniform general trends, indicating a universal aspect of energy flow in shear ruptures.