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SHOCK INITIATION PROPERTIES
4.5.3 Partial Reaction in Shocked Explosives. As a shock wave passes through
an explosive, some reaction usually occurs behind the wave front. If the shock wave
,is strong enough, the decomposition can build up to a detonation. There are few ex-
perimental data or theories that describe this process, but the following data give
evidence of its effect in one configuration.
Figure 4.24 shows the experimental arrangement. A plane-wave shock of known
amplitude was transmitted into one side of the test explosive, and the free-surface
velocity of a witness plate on the opposite side was measured. The explosive
thickness was varied for each input shock amplitude. If the explosive were totally
inert, the witness plate free-surface velocity would be expected to decrease slightly
with increasing explosive thickness and constant input shock. Instead, as the data
show, the velocity increases, indicating that energy is added to the transmitted
shock from shock-induced reaction in the explosive. Unfortunately, there are no
similar data with the explosive as an inert. They would allow the reaction to be
characterized quantitatively as a free-surface velocity increase for a particular
shock pressure and run distance in the explosive. These data were included with the
hope that they can be useful and perhaps encourage further study of shock-induced
reaction.
Fig. 4.24. Experimental arrangement for producing partial reaction in shocked ex-
plosives.
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