Fragmentation of grains in a two-dimensional packing

A numerical model of fragmentation of a two-dimensional granular medium under pressure is investigated. The fragmentation process is found to be strongly dependent on the type of force used as the criterion for breaking the grains. The fragmentation mode affects the process less dramatically. There is a power-law divergence in the pressure when the medium approaches the full packing limit, $(\epsilon_c-\epsilon)^{-2.0}$. Both log-normal and power-law fragment-size distributions are found. Gravity is demonstrated to be an important factor