Cavity expansion analyses of crushable granular materials with state-dependent dilatancy

2011 ◽  
Vol 36 (6) ◽  
pp. 723-742 ◽  
Author(s):  
M. J. Jiang ◽  
Y. G. Sun
Keyword(s):  
Granular Materials ◽  
Cavity Expansion ◽  
State Dependent

scholarly journals Earthquake dynamics constrained from laboratory experiments: new insights from granular materials

2021 ◽  
Vol 64 (4) ◽  
pp. SE441
Author(s):  
Andrea Bizzarri ◽  
Alberto Petri ◽  
Andrea Baldassarri
Keyword(s):  
Granular Materials ◽  
Laboratory Experiments ◽  
Seismic Waves ◽  
Laboratory Data ◽  
Numerical Approach ◽  
Earthquake Dynamics ◽  
Friction Behavior ◽  
Dynamic Propagation ◽  
State Dependent ◽  
Basic Features

The traction evolution is a fundamental ingredient to model the dynamics of an earthquake rupture which ultimately controls, during the coseismic phase, the energy release, the stress redistribution and the consequent excitation of seismic waves. In the present paper we explore the use of the friction behavior derived from laboratory shear experiments performed on granular materials at low normal stress. We find that the rheological properties emerging from these laboratory experiments can not be described in terms of preexisting governing models already presented in literature; our results indicate that neither rate–and state–dependent friction laws nor nonlinear slip–dependent models, commonly adopted for modeling earthquake ruptures, are able to capture all the features of the experimental data. Then, by exploiting a novel numerical approach, we directly incorporate the laboratory data into a code to simulate the fully dynamic propagation of a 3–D slip failure. We demonstrate that the rheology of the granular material, imposed as fault boundary condition, is dynamically consistent. Indeed, it is able to reproduce the basic features of a crustal earthquake, spontaneously accelerating up to some terminal rupture speed, both sub– and supershear.

scholarly journals Experimental Method for Examination of State Dependent Friction

2015 ◽  
Vol 11 (1) ◽  
pp. 29-42 ◽  
Author(s):  
Ferenc Safranyik ◽  
Attila Csatár ◽  
Attila Varga
Keyword(s):  
Experimental Method ◽  
Granular Materials ◽  
Time Dependent ◽  
Direct Shear ◽  
Friction Process ◽  
State Dependent ◽  
Almost All ◽  
Direct Shear Apparatus

The phenomenon of friction reduces efficiency of almost all machines in practice. In order to reduce the deficits, we have to understand this phenomenon and have to take it into consideration during design in all cases. Nevertheless, in certain cases describing of a friction process is very difficult, because it depends on a lot of parameters. In case of polymers, granular materials or in geology, the rate and state dependent friction have great importance. In this paper, velocity and time dependent friction is examined with the help of a direct shear apparatus, which was developed in our earlier work.

Dissipation in granular materials

1998 ◽  
Vol 77 (5) ◽  
pp. 1413-1425 ◽  
Author(s):  
Dietrich E.Wolf, Farhang Radjai, Sabine Dipp
Keyword(s):  
Granular Materials
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