Topological complexity of frictional interfaces: friction networks

Abstract

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) ∝ k β (β ≈ 2 ± 0.3)). 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).

Acoustic-Friction Networks and the Evolution of Precursor Rupture Fronts in Laboratory Earthquakes

“…The method was used over the recorded time-series from acoustic transducers. A similar method has been used on real-time contact areas and apertures of frictional interfaces2930. Other techniques-also-have been introduced into the study of time series analysis, such as the approaches based on the concept of a quasi-periodic cycle43 correlations44 visibility45 transition probabilities46 recurrence analysis (phase-space reconstruction)474849.…”

“…We use a “closeness” metric: . To choose a threshold level, we follow the employed method in2930, in which the minimum variation of local flow energy with the threshold level is considered as a criterion to the best threshold level. To precisely analyze a time series with the aforementioned methods and reduce possible errors due to the limited number of stations, we set m = 1 (equal to each recorded point).…”

Complex networks and waveforms from acoustic emissions in laboratory earthquakes

“…In Fig. 1d of Ghaffari and Young (2012b), we showed that selecting the threshold level by using the minimum variation of B.C versus ξ is equivalent with finding the most stable structures in networks. We note that the truncation level (or an interval of that) determines the characteristics of the network.…”

Determining Crack Aperture Distribution in Rocks Using the 14C‐PMMA Autoradiographic Method: Experiments and Simulations

“…Weathering impacts the transport properties and permeability of the rock (Brown, 1989;Brown et al, 1998;Regenauer-Lieb et al, 2013b, 2013aTsang & Witherspoon, 1981, 1983, and the diffusion and transport of solutes into the rock (Bear et al, 1993;Grisak & Pickens, 1980Hellmuth et al, 1991Hellmuth et al, , 1994, because of the induced dissolution/precipitation reactions (Jamtveit et al, 2009(Jamtveit et al, , 2011Putnis, 2002Putnis, , 2009White et al, 2001). These changes in pore geometry and connectivity during rock alteration are coupled with changes of mechanical properties (Ghaffari et al, 2013;Ghaffari & Young, 2011;Rock, 2010;Rossi & Graham, 2010).…”