scholarly journals A Granular Physics‐Based View of Fault Friction Experiments

2020 ◽  
Vol 125 (6) ◽  
Author(s):  
Behrooz Ferdowsi ◽  
Allan M. Rubin
Keyword(s):  
Fault Friction ◽  
Granular Physics

scholarly journals Scanning geophysical hazards

2020 ◽  
Vol 51 (2) ◽  
pp. 14-16
Author(s):  
James Baker
Keyword(s):  
Complete Picture ◽  
Snow Avalanches ◽  
X Ray ◽  
Granular Physics ◽  
Fresh Insight

Granular physics, the study of how collections of macroscopic particles behave en masse, helps us to model geophysical hazards like snow avalanches and landslides. Before placing trust in any predictions, we need a complete picture of how opaque grains flow. X-ray technologies provide an unobtrusive means to see beyond the surface. Whereas classical tomography does not work for moving samples, new dynamic X-ray approaches can handle genuinely flowing regimes, offering fresh insight.

Understanding earthquake from the granular physics point of view — Causes of earthquake, earthquake precursors and predictions

2018 ◽  
Vol 32 (07) ◽  
pp. 1850081 ◽  
Author(s):  
Kunquan Lu ◽  
Meiying Hou ◽  
Zehui Jiang ◽  
Qiang Wang ◽  
Gang Sun ◽  
...  
Keyword(s):  
Large Scale ◽  
Continuum Theory ◽  
Earthquake Precursors ◽  
Point Of View ◽  
The Earth ◽  
Discrete Nature ◽  
Granular Physics ◽  
Deep Focus ◽  
Tectonic Forces ◽  
Precursory Information

We treat the earth crust and mantle as large scale discrete matters based on the principles of granular physics and existing experimental observations. Main outcomes are: A granular model of the structure and movement of the earth crust and mantle is established. The formation mechanism of the tectonic forces, which causes the earthquake, and a model of propagation for precursory information are proposed. Properties of the seismic precursory information and its relevance with the earthquake occurrence are illustrated, and principle of ways to detect the effective seismic precursor is elaborated. The mechanism of deep-focus earthquake is also explained by the jamming–unjamming transition of the granular flow. Some earthquake phenomena which were previously difficult to understand are explained, and the predictability of the earthquake is discussed. Due to the discrete nature of the earth crust and mantle, the continuum theory no longer applies during the quasi-static seismological process. In this paper, based on the principles of granular physics, we study the causes of earthquakes, earthquake precursors and predictions, and a new understanding, different from the traditional seismological viewpoint, is obtained.

Do granular systems obey statistical mechanics? A review of recent work assessing the applicability of equilibrium theory to vibrationally excited granular media

2017 ◽  
Vol 31 (10) ◽  
pp. 1742010 ◽  
Author(s):  
C. R. K. Windows-Yule
Keyword(s):  
Granular Media ◽  
Mechanical Energy ◽  
Theoretical Models ◽  
Canonical System ◽  
Granular Systems ◽  
Vibrationally Excited ◽  
Fundamental Physics ◽  
Physical Systems ◽  
Classical Systems ◽  
Granular Physics

Driven granular media — assemblies of discrete, macroscopic elements exposed to a source of mechanical energy — represent inherently out-of-equilibrium systems. Although granular media are ubiquitous in both nature and industry, due to their dissipative nature and resultant complex behaviors they remain startlingly poorly understood as compared to classical, thermodynamic systems. Nonetheless, in recent years it has been observed that the behaviors of granular media can, under certain circumstances, closely resemble those of equilibrium systems. One of the most important contemporary questions in the field of granular physics is whether these similarities are merely superficial, or whether the parallels run deep enough that the behaviors of these nonequilibrium systems can in fact be successfully captured using analogs to existing theoretical models developed for classical systems. In this review, we draw together the findings of a variety of recent studies where this question has been addressed, comparing and contrasting the results and conclusions presented. We focus our attention on vibrated and vibrofluidized granular beds, which provide a canonical system representative of various equilibrium and nonequilibrium physical systems, and whose simple dynamics offer a valuable testing ground for exploring the fundamental physics of the granular state.

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