O-053 A Connection Between Shock Sensitivity, Ignition Sensitiveness and System Explosiveness

December 1999
Dr Peter R. Lee (Project Manager)

After defining Sensitivity, Sensitiveness and Explosiveness, the paper examines analytical expressions governing shock initiation by projectile impact, several different non-shock processes of ignition of deflagration and high strain rate fracture mechanics of energetic materials. A unifying theme runs through all. It is the pre-eminence of the importance of the rate at which energy is deposited in the energeticmaterialwhich controls whether a givenmaterial is, or is not, initiated. Moreover, the same concept is related to the propensity to crack of an energetic material subjected to transient thermomechanical stimuli.

This finding paves the way for a unified theory of initiation and subsequent acceleration of deflagration to detonation, or deceleration to extinguishment. It also assists in the understanding of the observation that in some initiation regimes, e.g. fragment or spigot intrusion, there is a process where the severity of an event first increases as the intensity of the initating stimulus increases, then the severity decreases and finally increases again at a level of severe explosion or detonation.

Recommendations are made for design of standard small scale experiments, from which critical initiation parameters of energetic materials and propensity to crack of the same materials can be measured using the same units of energy deposited per unit mass, or unit volume of the energetic material over unit time.

Presentation details

This paper was presented to the Insensitive Munitions and Energetic Materials Technology Synposium held on 29 November-2 December 1999 in Tampa, Florida, USA