Breakage of granular materials is an extremely common and important phenomenon encountered in industries ranging from mining to pharmaceutical production. Despite the prevalence of breakage, the general mechanisms of converting an applied force into particle fracture is still largely unexplained, as experimental analysis is hindered by the small length and time scales typical of breakage events. Recently, numerical modeling has emerged as a viable approach to studying breakage behavior and is not susceptible to the shortcomings encountered with experimental studies of breakage. Here, bonded agglomerates constructed with the Bonded Particle Model (BPM) are impacted against a contact plate to develop an understanding of how microscopic simulation parameters affect macroscopic breakage. A range of bond and simulation parameters, as well as impact velocities, are tested and the resultant breakage demonstrates that a range of breakage behavior is realized, from a completely broken to completely unbroken agglomerate. Specifically, the bond parameters and impact velocity dominate the breakage behavior, while relatively minor effects are observed with other variations in simulation parameters. (C) 2011 Elsevier B.V. All rights reserved.