Crack pattern of indented cohesive granular media
Marie-Julie Dalbe1, Pierre Jodlowski1, Nicolas Vandenberghe1
1IRPHE, Centrale Med, CNRS, Aix Marseille Université, Marseille, France.
Physical Review. E
|September 16, 2025
Summary
This study shows that cohesive granular materials, like wet sand, can form cracks when indented, similar to brittle solids. Crack formation is linked to material dilation during shearing.
Area of Science:
- Geophysics
- Material Science
- Solid Mechanics
Background:
- Cohesive granular materials exhibit solid-like behavior before yielding.
- These materials can unexpectedly develop cracks, mimicking brittle material fracture.
- Understanding crack formation in granular media is crucial for predicting material failure.
Purpose of the Study:
- To investigate the mechanisms of crack formation during the indentation of cohesive granular materials.
- To characterize the resulting crack patterns and their relationship to material behavior.
Main Methods:
- Quasistatic indentation of a wet granular medium using a solid cylindrical indenter.
- Direct observation of crack patterns.
- Three-dimensional X-ray microtomography for detailed crack characterization.
Main Results:
- Radial cracks were observed to form during indentation.
- The observed cracks resemble mode I cracks found in brittle elastic solids.
- A direct correlation was established between material dilation during shearing and crack appearance.
Conclusions:
- Cohesive granular materials can exhibit brittle-like fracture behavior under specific loading conditions.
- Crack formation is intrinsically linked to the dilatant response of the granular material.
- The findings provide insights into fracture mechanics in granular systems.
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