Wang, YC & Alonso-Marroquin, F 2008, 'DEM Simulation of Rock Fragmentation and Size Distribution Under Different Loading Conditions', in Y Potvin, J Carter, A Dyskin & R Jeffrey (eds), SHIRMS 2008: Proceedings of the First Southern Hemisphere International Rock Mechanics Symposium, Australian Centre for Geomechanics, Perth, pp. 149-156, https://doi.org/10.36487/ACG_repo/808_168 (https://papers.acg.uwa.edu.au/p/808_168_Wang/) Abstract: Rock fracture and fragmentation plays an important role in earthquakes, structural engineering and comminution processes. Typically, measured fragment size distribution of a single breaking particle is given by power law relations. Those relations are independent of energy input or loading conditions. In this study, we use ESyS-Particle, the 3D parallel Discrete Element Model (DEM), to simulate rocks as an assemblage of bonded spherical particles. ESyS-Particle takes into account single particle rotation and full set of interactions between bonded particles. We reproduce the fracture process and calculate the size distribution of the fragments using two different loading conditions: 1) slow and quasi-static uniaxial compression of rock-like samples; 2) fast loading by throwing a sphere consisting of small bonded particles at a rigid wall. Realistic fracture patterns and fragment size distribution are obtained.