The dynamic compaction of sugar as a stimulant of HMX

The ability of confined porous energetic materials to transition to detonation under weak impact (less than 100 m/s) has been a safety concern for many years. Porosity increases the sensitivity of an explosive to impact by facilitating energy localisation to form ``hot spots.'' Granular materials have been studied for many years as mock porous explosives. Compaction dissipates energy; this can mainly be attributed to intergranular friction, material damage and material compression. Dissipation increases temperatures but key questions remain about how accurately continuum models quantify this dissipation. Quasi-static compaction experiments have demonstrated significant changes in bulk mechanical behaviour during loading and bed hysteresis, yet the models describe quasi-static compaction as fully reversible. To quantify the extent of dissipation during compaction, there is a need for dynamic compaction experiments undertaken over a range of strain rates. This article reports experiments on the loading response of sugar over a range of strain rates from quasi-static to fully dynamic. The experiments are used to provide closures for mathematical models of dynamic compaction and data to validate simulations.