Linking initial microstructure and local response during quasistatic granular compaction

Area of Science:

• Materials Science
• Physics
• Geology

Background:

• Granular materials are ubiquitous in nature and industry.
• Understanding compaction behavior is crucial for material design and geological processes.
• Microstructure significantly influences macroscopic properties of granular materials.

Purpose of the Study:

• To investigate the relationship between microstructure and local force/strain during quasistatic granular compaction.
• To identify predictors of regions vulnerable to high stress and deformation.
• To understand the microstructural origins of grain fracture.

Main Methods:

• Combined three-dimensional X-ray diffraction and X-ray computed tomography.
• Analyzed quasistatic granular compaction experiments.
• Correlated microstructural features (void space, coordination number) with mechanical responses (force, strain).

Main Results:

• Initial void space and coordination number predict regions of high force and strain.
• Correlations observed between void space and coordination number, and between grain stress and interparticle force.
• Fracturing grains exhibited above-average initial void space and below-average coordination number.

Conclusions:

• Microstructure evolution during compaction can be quantitatively described.
• A predictive approach for identifying vulnerable regions in granular materials is established.
• Methods for inferring interparticle forces and coordination numbers from stress and porosity are provided.