A Refined DEM Study of Grain Size Reduction in Uniaxial Compression

The elementary behaviour of granular materials strongly depends on microstructural and geometrical changes from grain crushing. This paper proposes a 2D discrete element numerical model for the investigation of brittle granular crushing in confined uniaxial compression conditions. While our analysis adopts the well established strategy of replacing pre-crushed particles by post-fractured fragments, our model is based on a refined fracture criterion that accounts for: (1) the Weibull statistics of the tensile strengths, (2) the effects of the coordination number and (3) the curvature of the loading particles. Further refinements enable the current model to conserve mass and to extend the contrast between the fragment sizes as they evolve. Given these technical achievements, the scientific purpose of the paper is to test the prevailing assumption that confined uniaxial compression of granular material is leaded towards an ultimate fractal grain size distribution (gsd): in particular, we question whether the system tends towards a power-law gradation and self-similar topology.