Discrete Element Method (DEM) is a numerical technique based on Newton's law of mechanics
initially designed to study the flow of granular materials (Cundall and Strack 1979). The
interaction between these materials and predefined environment are simulated using contact
models which calculates the forces and associated energy loss (Cundall and Strack 1979). As
DEM has been refined it has demonstrated the capability to study dynamic scenarios such as
earthquake rock fracture and comminution (Mora et al. 1993 Potyondy et al. 1996 Morrison
et al. 2007). These scenarios necessitated constructing numerical rock specimens of desired
shape and size and the implementation of breakage models within DEM. A number of breakage
models with variation in mathematical formulations and their mode of implementation have been
utilised in comminution studies. The most prominent are the Discrete Grain Breakage (DGB)
method (Potapov and Campbell 1994) Particle Replacement Method (PRM) (Cleary 2001) and the
Bonded Particle Model (BPM) (Potyondy and Cundall 2004). The DGB and PRM models are
semi-empirical replacing individual discrete rocks with a population of smaller rocks in
accordance with a prescribed appearance function. In BPM a rock specimen is represented by
connecting contacting discrete entities. The BPM aims to simulate rock breakage with fragmented
sizes and shapes determined dynamically i.e. shapes and size distributions of fragments arise
naturally.
