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Published on: May 20, 2018
Granular compaction under confinement
1Physics Department, Lake Forest College, Lake Forest, Illinois 60045, USA. mueggenburg@lakeforest.edu
Summary
Vertical vibrations compact granular materials, but this process is hindered by confining forces that limit dilation. Compaction rates depend on dilation, not shaking intensity or force magnitude.
Area of Science:
- Physics
- Materials Science
- Granular Dynamics
Background:
- Granular materials densify under vertical vibrations.
- Pack dilation during vibration is crucial for rearrangement and compaction.
- Confining forces can influence granular pack behavior.
Purpose of the Study:
- To experimentally investigate the effect of confining forces on granular pack compaction during vibrations.
- To determine how limiting dilation impacts the rearrangement and densification process.
Main Methods:
- Utilizing a confined granular pack subjected to successive vertical vibrations.
- Applying varying confining forces to restrict pack dilation.
- Measuring compaction and correlating it with dilation levels.
Main Results:
- Confining forces significantly reduce granular pack compaction.
- Compaction is primarily dependent on the extent of dilation, not shaking acceleration or force magnitude.
- Inhibiting dilation leads to very slow compaction, potentially reaching a critical packing fraction of ~0.6.
Conclusions:
- Confining forces play a critical role in inhibiting granular compaction by limiting dilation.
- The degree of dilation is a key factor governing the rate and extent of compaction in vibrated granular systems.
- Findings support the concept of a critical packing fraction for the onset of dilation in granular dynamics.
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