Voronoi-Based DEM Simulation Approach for Sandstone Considering Grain Structure and Pore Size

Abstract

This paper presents a new procedure to create numerical models considering grain shape and size as well as pore size in an explicit and stochastic equivalent manner. Four shape factors are introduced to reproduce shape and size of grains and pores. Thin sections are used to analyze grain shape and pore size of rock specimen. First, a particle-based numerical model is set up by best fitted clumps from a shape library according to thin sections. Finally, an equivalent Voronoi-based discrete element model is set up based on the superimposed particle model. Uniaxial compression and tensile tests are simulated for validation. Both tests indicate that grain boundaries and pores provide preferred paths of weakness for crack propagation, but they also reveal significant differences in terms of intra- and inter-granular fracturing.