Project

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Vibration-induced unjamming of sheared granular media: investigation by 3D Discrete Element Method modeling and simulation

English title Vibration-induced unjamming of sheared granular media: investigation by 3D Discrete Element Method modeling and simulation
Applicant Griffa Michele
Number 135492
Funding scheme Project funding (Div. I-III)
Research institution Abteilung Beton / Bauchemie EMPA
Institution of higher education Swiss Federal Laboratories for Materials Science and Technology - EMPA
Main discipline Civil Engineering
Start/End 01.05.2011 - 30.04.2014
Approved amount 162'159.00
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All Disciplines (8)

Discipline
Civil Engineering
Geology
Material Sciences
Geophysics
Other disciplines of Physics
Condensed Matter Physics
Mechanical Engineering
Theoretical Physics

Keywords (8)

Physics of granular media; Unjamming transition; Dynamic earthquake triggering; Multiscale mechanics of materials; Computational modeling; Discrete Element Method; Molecular Dynamics; High Performance Computing

Lay Summary (English)

Lead
Lay summary

This Research project aims at investigating the role of mechanical vibration in triggering the abrupt transition from a solid-like (jammed state) to a fluid-like (unjammed state) behavior of sheared granular layers. We specifically focus on understanding the underlying grain-scale processes.

 

This Research project is motivated by an ongoing collaboration between the investigators, the Los Alamos National Laboratory (LANL) and the Pennsylvania State University (PSU), USA.

 

The collaborators from PSU and LANL have been using a specific laboratory setup that was developed at PSU for investigating granular friction and its role in the physics of earthquakes.

 

, a layer of rock debris produced by wear during the tectonic relative sliding that generates earthquakes.i.e.In this setup a sheared granular layer is manipulated to mimic many different types of seismic events and dynamics, in particular stick-slip, which is the lab equivalent of one type of earthquake dynamics. The stick stage is associated to deformation of the tectonic blocks and accumulation of elastic energy. The slip stage corresponds to the earthquake event, accompanied by the release of the accumulated elastic energy. The laboratory granular layer mimics a geologic fault gouge,

 

Operating the PSU setup in the stick-slip dynamic regime, LANL/PSU researchers have found that lab analogs of earthquakes can be triggered upon subjecting the granular layer to transient elastic waves.

 

This lab phenomenology is similar to what has been observed just since the 1990s by seismologists: seismic waves, radiated by an earthquake, can trigger, later in time, the sudden transition from a solid-like to a fluid-like behavior for another geological fault at a different, far away, geographical location. This phenomenon is called “dynamic earthquake triggering” and remains a compelling mystery since its basic physical mechanisms are not yet understood. However, understanding dynamic earthquake triggering is of primary practical importance for improving seismic risk maps and for the prevention of other types of natural hazards, like snow avalanches and landslides.

 

The laboratory-scale experiments have some strong limitations: they do not give access to grain-scale measurements, thus they do not allow for understanding which grain-scale process is at the source of dynamic triggering of slip. In addition, the unjamming of sheared granular layers is a very complicated physical process of paramount importance in the field of Soft Condensed Matter and applied Materials Science. Indeed, unjamming is observed not only with granular media made of rigid macroscopic particles but also with colloids, suspensions, metallic glasses, other types of amorphous molecular solids and in applications at very small scales like particulate-based nanotribology. Unjamming of sheared granular media is not yet fully understood and remains a challenge for basic Materials Science because it involves both solid and fluid behavior, amorphous materials and dynamic phase transitions.

 

.Molecular Dynamics simulations based upon approach Computational Materials ScienceMotivated by the PSU/LANL experiments and by their limitations, we propose to contribute to investigating vibration-induced unjamming of sheared granular layers using a typical

 

We want to develop a computational model of the granular layers sheared in the PSU experimental apparatus and to simulate its behavior when perturbed by vibration.

Our major goal consists in unveiling the grain-scale mechanisms at the basis of dynamic triggering.

 

The project will consist of two main types of activities.

 

(1) 3D DEM modeling of sheared granular layers (a) in absence of applied vibration (reference datasets) and (b) in presence of it. No study has yet address modeling dynamic triggering with a such a configuration like the PSU’s one. We will focus our efforts onto (I) the implementation of realistic vibration source models by the use of elastodynamics simulations. (II) We will analyze the most relevant particle-scale parameters and processes to be included into the modeling for achieving better agreement with the observed lab phenomenology. We will constrain our models by laboratory datasets available by the LANL/PSU collaborators, who are leading investigators in the field (see articles in Nature 437: 71-874 (2005) and Nature 451: 57-61 (2008)).

 

(2) Development and implementation of measure functions for characterizing the grain-scale dynamics accompanying dynamic triggering. We have performed till now initial 2D studies showing that specific mesoscopic measures are needed to describe the highly spatially heterogeneous strain tensor fields that evolve during shear, their perturbation by applied vibration and its relation to the macroscopic slip events.

 

From a practical point of view, this project will provide fundamental help in deciphering the physics of earthquake nucleation and, thus, it will help with the prevention of natural hazards, like earthquake triggering by natural seismic events or even by human activities, e.g., enhanced geothermal energy production by hydro-fracturing (December 2006 Basel earthquake as an example) and landslide/snow avalanche initiation by construction or mining works.

 

However, the project will have a broader impact in improving the understanding of the dynamic behavior of granular and amorphous solids that exhibit metastable states in between the solid-like and fluid-like phases.
Direct link to Lay Summary Last update: 21.02.2013

Responsible applicant and co-applicants

Employees

Name Institute

Publications

Publication
Acoustically induced slip in sheared granular layers: Application to dynamic earthquake triggering
Ferdowsi Behrooz, Griffa Michele, Guyer Robert A., Johnson Paul A., Marone Chris, Carmeliet J. (2015), Acoustically induced slip in sheared granular layers: Application to dynamic earthquake triggering, in Geophysical Research Letters, 42, 9750-9757.
Discrete element modeling of triggered slip in faults with granular gouge: application to dynamic earthquake triggering
Ferdowsi Behrooz (2014), Discrete element modeling of triggered slip in faults with granular gouge: application to dynamic earthquake triggering, Doctoral and Habilitation Thesis, ETH Zürich, Zürich.
Effect of boundary vibration on the frictional behavior of a dense sheared granular layer
Ferdowsi Behrooz, Griffa Michele, Guyer Robert A., Johnson Paul A., Carmeliet Jan (2014), Effect of boundary vibration on the frictional behavior of a dense sheared granular layer, in Acta Mechanica, 225, 2227-2237.
Three-dimensional discrete element modeling of triggered slip in sheared granular media
Ferdowsi Behrooz, Griffa Michele, Guyer Robert A., Johnson Paul A., Marone C., Carmeliet J. (2014), Three-dimensional discrete element modeling of triggered slip in sheared granular media, in Physical Review E, 89, 042204.
Acoustic emission and microslip precursors to stick–slip failure in sheared granular material
Johnson P.A., Ferdowsi B., Kaproth B., Scuderi M., Griffa M., Carmeliet J., Guyer R.A., Le Bas P-Y., Marone C. (2013), Acoustic emission and microslip precursors to stick–slip failure in sheared granular material, in Geophysical Research Letters, 40, 5627-5631.
Influence of vibration amplitude on dynamic triggering of slip in sheared granular layers
Griffa M. Ferdowsi B. Guyer R. A. Daub E. G. Johnson P. A. Marone C. Carmeliet J. (2013), Influence of vibration amplitude on dynamic triggering of slip in sheared granular layers, in Physical Review E, 87(1), 012205-NA.
Microslips as precursors of large slip events in the stick-slip dynamics of sheared granular layers: A discrete element model analysis
Ferdowsi Behrooz, Griffa Michele, Guyer Robert A., Johnson Paul A., Marone C., Carmeliet J. (2013), Microslips as precursors of large slip events in the stick-slip dynamics of sheared granular layers: A discrete element model analysis, in Geophysical Research Letters, 40(16), 4194-4198.
Meso-mechanical analysis of deformation characteristics for dynamically triggered slip in a granular medium
Griffa M. Ferdowsi B. Daub E.G. Guyer R. Johnson P.A. Marone C. Carmeliet J. (2012), Meso-mechanical analysis of deformation characteristics for dynamically triggered slip in a granular medium, in Philosophical Magazine, 92(28-30), 3520-3539.
Vibration-induced slip in sheared granular layers and the micromechanics of dynamic earthquake triggering
Griffa Michele, Daub Eric Guido, Guyer Robert Allan, Johnson Paul Allan, Marone Chris, Carmeliet Jan (2011), Vibration-induced slip in sheared granular layers and the micromechanics of dynamic earthquake triggering, in Europhysics Letters, 96(1), 14001-1-14001-6.

Collaboration

Group / person Country
Types of collaboration
US Geological Survey United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
Earth Systems Science Computational Centre - Univ. of Queensland Australia (Oceania)
- in-depth/constructive exchanges on approaches, methods or results
Los Alamos National Laboratory - US Dept. of Energy United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication
Geologie-Endogene Dynamik - RWTH Aachen University Germany (Europe)
- in-depth/constructive exchanges on approaches, methods or results
Dept. of Geosciences - Pennsylvania State University United States of America (North America)
- in-depth/constructive exchanges on approaches, methods or results
- Publication

Scientific events

Active participation

Title Type of contribution Title of article or contribution Date Place Persons involved
18th International Conference on Nonlinear Elasticity in Materials (XVIII ICNEM) Talk given at a conference 3D MD Modeling of Slip Triggering in Sheared Granular Layers by Means of Boundary Vibration 09.06.2013 Ascona, Switzerland Griffa Michele; Ferdowsi Behrooz; Carmeliet Jan;
2nd Winter School on "Materials Deformation: Fluctuations, Scaling and Predictability" Poster 3D MD modeling of slip triggering in sheared granular layers by means of boundary vibration 17.02.2013 Les Houches, France Ferdowsi Behrooz; Griffa Michele; Carmeliet Jan;
17th Fall Seminar on Nonlinear Dynamics Poster 3D MD modeling of slip triggering in sheared granular media by means of boundary vibration 07.10.2012 Bayreuth, Germany Griffa Michele; Ferdowsi Behrooz; Carmeliet Jan;
8th European Solid Mechanics Conference Talk given at a conference How external vibration affects stick-slip dynamics in sheared granular layers: the micro- and meso-mechanics of dynamic earthquake triggering 09.07.2012 Gratz, Austria, Austria Griffa Michele; Carmeliet Jan; Ferdowsi Behrooz;
17th International Conference on Nonlinear Elasticity in Materials Talk given at a conference Statistics and Mesoscale Mechanics of 2D Stick-Slipping, Sheared Granular Layers: Improving Our Understanding of Dynamic Earthquake Triggering Physical Controls 01.07.2012 Cefalu', Italy Carmeliet Jan; Griffa Michele; Ferdowsi Behrooz;
European Geosciences Union General Assembly 2012 Talk given at a conference Mesoscopic Scale Analysis of Deformation Patterns for Dynamically Triggered Slip in Sheared Granular Layers 22.04.2012 Wien, Austria Ferdowsi Behrooz; Carmeliet Jan; Griffa Michele;
Winter School on "Materials Deformation: Fluctuations, Scaling, Predictability" Poster Deformation pattern and evolution of the internal structure of granular media during stick-slip dynamics: micromechanics of dynamic earthquake triggering 22.01.2012 Les Houches, France Carmeliet Jan; Ferdowsi Behrooz; Griffa Michele;
Conference "Instabilities Across the Scales III" Talk given at a conference Granular stick-slip and the micromechanics of dynamic earthquake triggering 06.06.2011 Palm Cove, Cairns, Australia, Australia Ferdowsi Behrooz; Griffa Michele; Carmeliet Jan;


Communication with the public

Communication Title Media Place Year
Media relations: print media, online media About to crack 1663. Los Alamos Science and Technology Magazine International 2014
New media (web, blogs, podcasts, news feeds etc.) Faults may emit earthquake warning signs http://www.livescience.com International 2014

Awards

Title Year
Centro "Stefano Franscini" (CSF), ETHZ, Award for the best oral presentation by young scientists during the 18th International Conference on Nonlinear Elasticity in Materials (XVIII ICNEM), June 9th - 14th 2013, CSF, Ascona, Switzerland. 2013

Associated projects

Number Title Start Funding scheme
128754 UP-IPAZIA: “UPgrade and full deployment of the Empa/Eawag computational cluster IPAZIA: towards an interdisciplinary on-site resource for computational sciences” 01.04.2010 R'EQUIP

Abstract

This Research project aims at investigating the role of mechanical vibration in triggering the abrupt transition from a solid-like (jammed state) to a fluid-like (unjammed state) behavior of sheared granular layers. We specifically focus on understanding the underlying grain-scale processes. Recent observations in the Earth and Environmental Sciences underline the need and importance of this research topic since the physics of earthquakes is fundamentally related to the physics of granular media.At the center stage of this physics there is the fault gouge, Fig. 1, a granular layer of rock debris produced by wear during the relative sliding that generates earthquakes. A geologic fault remains stable up to the point the gouge behaves like a solid, bearing the shear load imposed by the surrounding rocks. The opposite blocks of the fault abruptly start to slide, accompanied by a huge release of accumulated strain energy (earthquake), when the gouge suddenly switches to a fluid-like behavior.Recent seismological observations have suggested that seismic waves, radiated by an earthquake, can trigger later in time this sudden transition for another geological fault at a different, far away, geographical location. This phenomenon is called “dynamic earthquake triggering” and remainsa compelling mystery since its basic physical mechanisms are not yet understood. However, understanding dynamic earthquake triggering is of primary practical importance for improving seismic risk maps.To investigate the earthquake physics in controlled conditions, a specific laboratory setup has been realized at the Pennsylvania State University (USA), which we will call here “earthquake machine”. In this setup a sheared granular layer is manipulated to mimic many different types of seismic events and dynamics, in particular stick-slip, which is the lab equivalent of one type of earthquake dynamics. Operating the earthquake machine in this particular dynamic regime, researchers have found that lab analogs of earthquakes can be triggered upon subjecting the granular layer to transient elastic waves.These laboratory-scale experiments have a strong limitation: they do not give access to grain-scale measurements, thus they do not allow for understanding which grain-scale process is at the source of dynamic triggering of slip.Motivated by these experiments and their limitation, we propose to develop a computational model of the granular layers sheared in the earthquake machine and to simulate its behavior when perturbed by vibration.Our major goal consists in unveiling the grain-scale mechanisms at the basis of dynamic triggering using 3D particle-based modeling and numerical simulations, by the Discrete Element Method (DEM), a type of Molecular Dynamics approach. The project consists of two main types of activities.(1) 3D DEM modeling of sheared granular layers (a) in absence of applied vibration (reference datasets) and (b) in presence of it. The two types of simulations are needed for characterizing the unjamming/slip process and understanding how vibration can trigger it. No study has yet address modeling dynamic triggering with a configuration similar to the earthquake machine. We will focus our efforts to (I) the implementation of realistic vibration source models by the use of elastodynamics simulations. In this way, it will be possible to investigate the role of the most important vibration parameters. (II) We will analyze the most relevant particle-scale parameters and processes to be included into the modeling for achieving better agreement with the observed lab phenomenology. We will constrain our models by laboratory datasets available by leading investigators in the field (P.A. Johnson, Los Alamos National Laboratory, C. Marone, Pennsylvania State University, see articles in Nature 437: 871-874 (2005) and Nature 451: 57-61 (2008)), collaborating to this project.(2) Development and implementation of measure functions for characterizing the grain-scale dynamics accompanying dynamic triggering.We have performed initial 2D studies showing that specific mesoscopic measures are needed to describe the highly spatially heterogeneous strain tensor field that evolves during shear, its perturbation by applied vibration and its relation to the macroscopic slip events. These measures still need to be implemented, validated and eventually re-adapted to the 3D case. This type of activity, in our opinion, is very challenging. However, it is strongly necessary for (a) a meaningful analysis of the simulation datasets, (b) their comparison with the experimental ones and (c) achieving the long term goal of developing macroscopic constitutive equations that are general enough to capture the basic statistical features of dynamic triggering but that take also into account the relevant granular processes at the different scales.This project will provide fundamental help in deciphering the physics of earthquake nucleation and, thus, it will have a broader outreach in terms of helping with the prevention of natural hazards, like earthquake triggering by natural seismic events or even by human activities, e.g., enhanced geothermal energy production by hydro-fracturing (December 2006 Basel earthquake as an example) and landslide/snow avalanche initiation by construction or mining works.
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