A LAMMPS implementation of granular mechanics: Inclusion of adhesive and microscopic friction forces

A model for μm-sized grain-grain interaction is presented, which exhibits the essential features necessary to describe collision, agglomeration and fragmentation processes. The model has been efficiently implemented in the LAMMPS code. In addition to existing models, adhesive forces and - gliding, rolling, and torsional - friction processes are implemented. The code scales linearly with grain number up to ∼106 on a single processor and inherits the excellent parallelization features of the LAMMPS code on multi-processor machines. We validate the code by determining the velocity of sound of granular agglomerates.