Use of acoustic emission to study the breakdown of explosive products

Acoustic emission (AE) was used to investigate the breakdown of products formed from fiber-reinforced explosives under mechanical loading. Acoustic emission was measured during the tensile and compressive testing of the explosives, and with hollow products loaded under internal pressure. Specimens were tested prior to and after being subjected to thermal effects. It was established that breakdown of crystals in the explosive filler provides the basic contribution to the AE effect. It is demonstrated that as for many other materials exhibiting acoustic activity, the Kaiser effect and the effect of a sudden change in AE during crack formation is characteristic of the explosive under investigation. It is also established that the breakdown of hollow products is discontinuous in nature under internal pressure. The results of the investigation suggest the potential of the AE method for investigation of changes in the structure of explosives subsequent to various external effects.Russian Federal Nuclear Center, All-Union Scientific-Research Institute of Experimental Physics, Sarov, Russia. Translated from Mekhanika Kompozitnykh Materialov, Vol. 32, No. 6, pp. 818–823, November–December, 1996.