Micromechanical Origin of Particle Size Segregation
L Jing1, C Y Kwok1, Y F Leung2
1Department of Civil Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
Physical Review Letters
|April 4, 2017
Summary
This study reveals how particle size segregation occurs under shear. Small particles move through gaps, while large particles climb via rotation and friction in dense granular flows.
Area of Science:
- Granular physics
- Computational mechanics
Background:
- Size segregation is a common phenomenon in granular materials.
- Understanding the underlying micromechanics is crucial for controlling granular flow.
Purpose of the Study:
- To computationally investigate shear-induced size segregation in granular systems.
- To elucidate distinct migration mechanisms for large and small particles.
Main Methods:
- Micromechanical simulations of granular flow under shear.
- Analysis of particle-particle interactions and contact networks.
Main Results:
- Small particles percolate through voids without significant contacts.
- Large particles migrate upwards through anisotropic contact networks, requiring rotation.
- Interparticle friction enhances large particle migration but minimally affects small particle percolation.
Conclusions:
- Distinct mechanisms govern the migration of large and small particles during shear-induced segregation.
- Particle rotation and interparticle friction are critical factors influencing large particle segregation.
