FDEM Simulation of Rocks with Microstructure Generated by Voronoi Grain-Based Model with Particle Growth

Rock strength variation is closely related to its microstructure. With the development of computer technology, the numerical model of rocks can be constructed via computer programming, and the numerical simulation avoids a mass of redundant experimental tests and usually limited by the samples retrieved from the sub-surfaces. In previous studies, the microstructure in the numerical model is generated randomly. In this paper, a novel methodology for generating the polycrystalline rock microstructure by a Voronoi grain-based model with particle growth is proposed. The 3D Voronoi tessellations in this numerical model generation procedure do not consist of random poly-crystals; the distribution of the poly-crystals varies in shapes and sizes, which represent different mineral grains, and is determined by petrographic data with the 3D particle growth method. The uniaxial compression tests and tension tests are simulated via a combined FDEM and cohesive crack propagation model. The results demonstrate that the numerical simulation agrees well with the experimental study. More importantly, the fracture patterns in the micro-scale are gained, similar to the results obtained from laboratory experiments. The novel Voronoi grain-based model with the particle growth method can reconstruct the microstructure of polycrystalline rocks and provide further information in understanding the micro-behaviors of rock materials.