Shock sensitivity of explosives

Transition of combstn to deflgrn in expls. Combstn of powdered expls at high constant pressures) 11) J. Eadie, "The Effect of Wax on the Shock Sensitivity of Explosive Compacts , 4thONRSympDeton(l965), 399-403 12) J.E. Hay et al, "The Effect of Physical and Chemical Properties on the Sensitivity of Liquid Explosives , 4thONRSympDeton... 

Initiation by Shock will be described in detail under Shock Sensitivity. Some of the tests for determining the shock sensitivity of explosives have already been given under Detonation (and Explosion) Experimental Procedures in Vol 4, pp D318-321, pp D322-331 D344. Some preliminary discussion of shock initiation is also given in Vol 4, pp D520-522... 

NOL data from Ref 32 (recomputed in Ref 42a) are summarized in Table 5. The terms SSGT and LSGT are NOL descriptions for their usual gap tests (see under Shock Sensitivity of Explosives 1 in this Vol)... 

The obvious importance of the thermal expln of hot spots in the theoretical description of the initiation of detonation by impact or shock was presented in Vol 7, H170-175,143-55, L31-32, and in this Vol under Shock Initiation , a section under Shock Sensitivity of Explosives Conse-... 

Shock sensitivity of explosive substances with low or medium sensitivity. 

The shock sensitivity of explosive substances can be examine over a wide range by combining the small gap test and the variable initiator test. The results of the two experiments can be shown in one diagram. Although this procedure may not be based on rigorous theory, we show the results of its application in Fig.3.86. 

An explosion of HE may also be initiated by severe shock. Sensitivity of explosives to shock may be measured in several ways, such as the impact pendulum method and the drop test. In the impact pendulum test, a heavy pendulum swings down over a sample... 

Donor-acceptor tests, employing gaps between the donor and the acceptor, have been used to measure the shock sensitivities of explosives. The small-scale gap test is a refined version which employs a steel dent block and Lucite in the gap [1]. The gap decibang (dbg), analogous to the decibel, but relative to a reference level, is used as a measure of the stimulus ... 

Tetryl has been used as an expl since 1906. In the early part of this century it was frequently used as the base charge of blasting caps but is now replaced by PETN or RDX. During WWII it was used as a component of expl mixts (see Tetrytols in this Vol). Tetryl is still used in military boosters and leads (the expl component of a fuze between the detonator and booster), but even here it is being replaced by plastic-bonded or waxed RDX and HMX expls. A widely used shock sensitivity test employs Tetryl as the donor charge (see Shock Sensitivity of Explosives in this Vol)... 

The relative shock sensitivities of explosive compositions are commonly assessed by means of gap tests. In these tests, the shock from a standard donor explosive is transmitted to the test explosive through an inert barrier (the so called gap ). The shock sensitivity of the test explosive is characterized by the gap thickness for which the probability of detonation is 50%. In reference 26, the Los Alamos standard gap test and the Naval Ordnance Laboratory (NOL) large scale gap test were modeled using the 2DE code with Forest Fire burn rates. The Los Alamos gap test uses Dural for the inert barrier while the NOL gap test uses Plexiglas. The test explosive is unconflned in the Los Alamos gap test. In the NOL gap test the test explosive is confined with steel. The model showed good agreement between the calculated and experimental gap test values for PBX-9404, PBX-9502, Pentolite, Composition B, and an HMX based propellant, VTQ-2. 

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