Microscopic Origin of Nonlocal Rheology in Dense Granular Materials.

Area of Science:

• Physics
• Materials Science
• Engineering

Background:

• Granular materials exhibit complex behaviors like nonlocality.
• Understanding the microscopic origins of macroscopic properties is crucial.

Purpose of the Study:

• To investigate the microscopic origins of nonlocality in dense granular media.
• To develop a unified constitutive law for granular material behavior.

Main Methods:

• Discrete element simulations were employed.
• Analysis focused on microscopic elementary rearrangements and velocity fluctuations.

Main Results:

• Macroscopic shear arises from balanced microscopic rearrangements.
• Velocity fluctuations control effective macroscopic fluidity and nonlocal effects.
• A new micromechanically based unified constitutive law was defined.

Conclusions:

• The study elucidates the microscopic basis of nonlocality in granular media.
• The developed constitutive law accurately describes both quasistatic and inertial regimes.