Grain breakage under uniaxial compression, through 3D DEM modelling

Abstract

A breakable grain model is presented, using the concept of particles assembly. Grains of polyhedral shapes are generated, formed by joining together tetrahedral subgrains using cohesive bonds. Single grain crushing simulations are performed for multiple values of the intra-granular cohesion to study the effect on the grain's strength. The same effect of intra-granular cohesion is studied under oedometric compression on samples of around 800 grains, which allows the evaluation of grain breakage model on the macroscopic behaviour. Grain size distribution curves and grain breakage ratios are monitored throughout the simulations.

Oedometric compression of a granular material: computation of energies involved during breakage with a discrete element modelling

“…A breakage energy is then computed, by considering it equal to the difference between the two curves in figure 4. This breakage energy corresponds physically to the sum of two energies: an energy necessary for the creation of new surfaces by breakage of grains Esurf, and an energy due to the rearrangement of fragments resulting from the fracture Eredist [9,10] proposed by equation ( 3) in order to compute the surface creation energy per unit of volume produced by the fracture of the grains :…”