Evolution of force networks in dense particulate media

Area of Science:

• Physics
• Materials Science
• Complex Systems

Background:

• Dense particulate systems exhibit complex force network dynamics.
• Understanding these dynamics is crucial for predicting material behavior, especially during jamming transitions.
• Traditional methods struggle to capture the evolving geometric features of interparticle forces.

Purpose of the Study:

• To develop and apply a novel approach using persistent homology to quantify the dynamical properties of force networks in dense particulate systems.
• To analyze the evolution of force network geometry during the jamming transition.
• To investigate the role of friction in these dynamical properties.

Main Methods:

• Utilized discrete element simulations for two-dimensional systems of compressible frictional circular disks.
• Applied persistent homology to extract quantitative measures of force network evolution.
• Analyzed both connected components (force chains) and loops, considering normal and tangential forces.
• Compared frictional and frictionless systems.

Main Results:

• Identified localized changes in unjammed systems and global changes during jamming.
• Observed significantly less dramatic evolution in jammed states.
• Found that both connected components and loops provide valuable insights into network evolution.
• Confirmed consistent evolution of normal and tangential forces.
• Demonstrated that friction plays a critical role in network dynamics.

Conclusions:

• Persistent homology offers a precise and tractable method for describing force network evolution in particulate systems.
• The approach can reveal features difficult to discern with other methods.
• Friction is a key factor governing the dynamical properties of these force networks, impacting their evolution through jamming.