Computer simulation of model cohesive powders: influence of assembling procedure and contact laws on low consolidation states
arXiv:0705.3295 · doi:10.1103/PhysRevE.75.011303
Abstract
The structure and mechanical properties of a simple two-dimensional model of a cohesive powder are investigated by molecular dynamics simulations. Micromechanical ingredients involve elasticity, friction, a short range attraction and, possibly, rolling resistance (RR) in contacts. The microstructure of the cohesive packing varies according to the assembling procedure, from rather densely packed if isolated particles are directly compressed to much looser if the formation of large aggregates is allowed prior to compression. A crucial parameter is the ratio P*= Pa/F0 of applied pressure P, acting on grains of diameter , to maximum tensile contact force F0. At low P* the final structure depends on the level of velocity fluctuations at the early stages of cluster aggregation. With RR the coordination number approaches 2 in the limit of low initial velocities or large rolling friction. The force network generally comprises small hyperstatic clusters with forces of the order of F0, joined by nearly unstressed, barely rigid arms. As P* grows, it quickly rearranges into force chain-like patterns. Density correlations witness a fractal structure, with dimension Df, up to some density-dependent blob size. WIth RR Df coincides with the ballistic aggregation result, despite a possibly different connectivity. Possible effects of some parameters on material strength are evoked.
31 pages Only 26 pages in the published PRE paper, but figures look better in THIS version !
References in corpus (21)
- A model for collisions in granular gases
- Force Distribution in a Granular Medium
- A Model for Force Fluctuations in Bead Packs
- Packing of Compressible Granular Materials
- Geometry of Frictionless and Frictional Sphere Packings
- The Geometrical Structure of Disordered Sphere Packings
- Granular Packings: Nonlinear elasticity, sound propagation and collective relaxation dynamics
- Shear strength properties of wet granular materials
- Force distributions in 3D granular assemblies: Effects of packing order and inter-particle friction
- Geometric origin of mechanical properties of granular materials
- Isostatic phase transition and instability in stiff granular materials
- Stress Propagation through Frictionless Granular Material
- Elastic wave propagation in confined granular systems
- Analysis by x-ray microtomography of a granular packing undergoing compaction
- Investigating the Geometrical Structure of Disordered Sphere Packings
- Quasistatic rheology and the origins of strain
- Computer simulation of model cohesive powders: Plastic consolidation, structural changes and elasticity under isotropic loads
- Plug flow and the breakdown of Bagnold scaling in cohesive granular flows
- Pore Stabilization in Cohesive Granular Systems
- Dynamic Rearrangements and Packing Regimes in Randomly Deposited Two-Dimensional Granular Beds
- The effect of contact torques on porosity of cohesive powders
Cited by in corpus (21)
- Internal states of model isotropic granular packings. I. Assembling process, geometry and contact networks
- Effect of cohesion on shear banding in quasi-static granular material
- A constraint-based approach to granular dispersion rheology
- The jamming transition and new percolation universality classes in particulate systems with attraction
- Flow of wet granular materials: a numerical study
- Computer simulation of model cohesive powders: Plastic consolidation, structural changes and elasticity under isotropic loads
- Internal states of model isotropic granular packings. II. Compression and pressure cycles
- Effect of long-range repulsive Coulomb interactions on packing structure of adhesive particles
- Jamming in Granular Polymers
- Compressive consolidation of strongly aggregated particle gels
- Restructuring of colloidal aggregates in shear flow: Coupling interparticle contact models with Stokesian dynamics
- Heterogeneous structure of granular aggregates with capillary interactions
- Simple Model for Wet Granular Materials with Liquid Clusters
- Athermal rheology of weakly attractive soft particles
- Discontinuous shear-thinning in adhesive dispersions
- Micro-mechanical insights into the stress transmission in strongly aggregating colloidal gel
- Macromechanical behavior of oxide nanopowders during compaction processes
- Ultraslow settling kinetics of frictional cohesive powders
- Méthodes quasi-statiques pour la simulation numérique discrète des assemblages granulaires
- Elastic Properties, Yield Surface and Flow Rule of Nanopowder Compacts
- Polygons vs. clumps of discs: a numerical study of the influence of grain shape on the mechanical behaviour of granular materials