Crystallization in load-controlled shearing flows of monosized spheres

Area of Science:

• Physics of granular materials
• Computational physics
• Materials science

Background:

• Granular materials exhibit complex flow and crystallization behaviors under shear.
• The role of inter-particle friction in these phenomena is not fully understood.

Purpose of the Study:

• To investigate the impact of inter-particle friction on the crystallization and flow dynamics of sheared identical, inelastic spheres.
• To analyze the influence of applied load on friction-dependent granular behavior.

Main Methods:

• Discrete element simulations were employed to model the behavior of sheared granular assemblies.
• Systematic variation of the inter-particle friction coefficient and applied load.

Main Results:

• At low loads near the crystallization threshold, small friction creates shear bands and crystalline regions, increasing shear resistance.
• Increased friction at low loads disrupts ordering, leading to fluidization and reduced shear resistance compared to frictionless cases.
• At higher loads, distinct core shear bands and boundary crystalline regions form, with shear resistance becoming independent of friction.

Conclusions:

• Inter-particle friction significantly alters the flow regime and crystallization of sheared granular materials.
• The applied load dictates whether friction enhances or reduces shear resistance and influences the spatial organization of ordered and disordered zones.