Compaction mechanics of a polydisperse crushable spherical granular assembly using discrete element method

The macroscopic behaviour of an assembly of polydisperse spherical particles is studied using a numerical model based on discrete element method (DEM), which accounts for the microscopic interactions between individual particles and their damage. DEM models particle–particle interactions enabling to understand the influence of microscopic particle–particle interactions on the macroscopic response. The method is used to stimulate the mechanical response of a polydisperse particle assembly under uniaxial compressive load. The influence of damage rate and the initial packing fraction on the macroscopic stress–strain response is investigated. The analysis shows that the initial nonlinear elastic behaviour is influenced by the initial packing factor, whereas the critical stress is influenced by both initial packing fraction and damage rate. It is also observed that critical stress occurs when the assembly reaches a particular damage state. Furthermore, the failure behaviour of different sized particles within a polydisperse assembly is also investigated. The experimental data from the literature show that the crush strength of the particle of given size is observed to vary over a range. Such variation of crush strengths for a given particle size is also implemented in the present work.