Coupled tomography and distinct-element-method approach to exploring the granular media microstructure in a jamming...

Area of Science:

• Physics
• Engineering
• Materials Science

Background:

• Granular media exhibit complex behaviors, such as arching, which are difficult to study at a microscopic level.
• Traditional methods often lack the resolution to capture the intricate dynamics of granular systems.

Purpose of the Study:

• To develop and validate a novel approach for exploring microscopic properties of granular media.
• To investigate the phenomenon of instant arching in granular materials using advanced simulation and imaging techniques.

Main Methods:

• Coupling X-ray microtomography for 3D imaging with distinct-element-method (DEM) simulations.
• Developing specialized image analysis to extract bead geometry (positions, sizes) from tomographs, significantly reducing data size.
• Bridging the time gap between imaging snapshots using DEM simulations.

Main Results:

• DEM simulations accurately predict bead positions, showing good agreement with X-ray images.
• Image analysis successfully compressed large 3D tomographic data (5 GB to tens of KB).
• Sensitivity analysis revealed that accurate bead size estimation is more critical than position for modeling granular mixtures.

Conclusions:

• The coupled X-ray microtomography and DEM approach provides a powerful tool for granular media research.
• Understanding the critical role of bead size accuracy is essential for modeling polydisperse granular systems.
• Limitations exist in numerically reproducing non-equilibrium granular flows due to their chaotic nature.