Correlation and shear bands in a plastically deformed granular medium
Kamran Karimi1, Jean-Louis Barrat2
1Université Grenoble Alpes, CNRS, ISTerre, 38000 Grenoble, France. kamran.karimi@univ-grenoble-alpes.fr.
Scientific Reports
|March 7, 2018
Summary
This study reveals how local friction influences deformation patterns in granular solids. A mesoscale model explains microscopic correlations and macroscopic shear bands, differing from purely elastic interpretations.
Area of Science:
- Physics
- Materials Science
- Geophysics
Background:
- Granular solids exhibit complex deformation patterns under stress.
- Previous studies interpreted local deformation using elasticity theory and Eshelby transformations.
- A discrepancy exists between microscopic correlation angles and macroscopic shear band angles.
Purpose of the Study:
- To interpret the anisotropic correlations in local deformation of granular solids.
- To explain the difference between microscopic correlation angles and macroscopic shear band angles.
- To incorporate a local failure criterion into deformation models.
Main Methods:
- Developed a mesoscale elastoplastic model for solid flow.
- Incorporated a local Mohr-Coulomb failure criterion.
- Analyzed the combination of elastic interactions and local friction.
Main Results:
- The model successfully explains the characteristic angle of microscopic correlations by combining Eshelby transformations with a local failure criterion.
- Permanent shear bands at large strains form at a different angle, corresponding to maximal slip line instability.
- This provides an alternative interpretation to purely elastic models.
Conclusions:
- Local friction and failure criteria are crucial for understanding deformation patterns in granular materials.
- The mesoscale elastoplastic model offers a more comprehensive explanation for observed phenomena.
- The study reconciles microscopic and macroscopic deformation behaviors in granular solids.
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