Modelling the effect of friction on explosives

Abstract

The Atomic Weapons Establishment (AWE) investigate the safe use and handling of high explosives. High explosives are inherently dangerous and their detonation can be triggered by low velocity impacts with speeds in the range of 10 to 70 m/s . The kinetic energy associated with impact is converted into thermal energy within the explosive, potentially leading to thermal runaway and detonation. The study group was asked to investigate the mechanisms generating heat and detonation in an explosive HMX, based on the compression of a sample of the explosive. The study group identified frictional heating in localized shear bands as the most likely mechanism for heat generation in the compression of both HMX and other high explosives formed from a granular material within a polymer bonding. The study group also considered the squeezing of explosive samples for a range of more general rheologies and investigated possible improvements to the numerical modelling already conducted by AWE.