Related Experiment Videos
Reorganization of a dense granular assembly: the unjamming response function
Evelyne Kolb1, Jean Cviklinski, José Lanuza
1Laboratoire des Milieux Désordonnés et Hétérogènes, UMR 7603, Université Pierre et Marie Curie, Boîte 86, 4 Place Jussieu, 75252 Paris Cedex 05, France.
Summary
We studied granular materials under stress, finding a long-range response and quasi-reversible behavior with persistent flow patterns after cyclic forcing. This reveals key mechanical properties of dense granular assemblies.
Area of Science:
- Physics
- Materials Science
- Geophysics
Background:
- Granular materials exhibit complex mechanical behaviors under stress.
- Understanding their response to local forcing is crucial for various applications.
Purpose of the Study:
- To investigate the mechanical properties of static dense granular assemblies.
- To analyze the response to local cyclic forcing in a 2D disordered packing.
Main Methods:
- Applying small cyclic displacement to a grain in the bulk.
- Monitoring displacement fields within the granular assembly.
- Analyzing the response under gravity in a 2D disordered packing.
Main Results:
- A dominant long-range radial response was observed above the point of solicitation.
- The system demonstrated quasi-reversible behavior after numerous cycles.
- A remanent dissipation field with long-range streams and vortex-like symmetry was identified.
Conclusions:
- Dense granular assemblies exhibit complex, long-range mechanical responses to local forcing.
- Quasi-reversibility and persistent dissipation patterns are key characteristics.
- The findings provide insights into the fundamental mechanics of granular materials.