Rotating bearings in regular and irregular granular shear packings.

Area of Science:

• Physics
• Materials Science
• Geophysics

Background:

• Shear deformation in 2D regular dense packings of disks involves theoretical bearing formation models.
• Extending these models to random packings, which better represent natural systems, is challenging.

Purpose of the Study:

• To numerically simulate shear deformation in both regular and random dense disk packings.
• To compare the formation and characteristics of rotating particle clusters in these different packing structures.

Main Methods:

• Utilized a numerical model to simulate shear deformation in 2D disk packings.
• Analyzed both near-regular and irregular packing configurations.
• Investigated the density and size distribution of rotating clusters near the jamming threshold.

Main Results:

• Rotating bearing structures form with similar densities in both random and regular packings.
• Significant differences were observed in the size distribution of rotating clusters near the jamming threshold.
• Regular packings showed a size cut-off that grows unboundedly at the jamming threshold, unlike finite cut-offs in irregular packings.

Conclusions:

• The study reveals similarities in bearing formation but distinct cluster dynamics between regular and random packings.
• The findings on cluster size distribution near jamming are crucial for understanding yielding phenomena.
• These insights have implications for natural processes such as landslides, snow avalanches, and tectonic fault behavior.