Gap test experiments used to study the sensivity of granular explosives

Explosives are widely used in medium to large calibre projectiles to increase the damage on a target. The ammunition produced by Nammo Raufoss, has superb qualities concerning penetration and fragmentation in a target. Enhanced fragmentation effect is achieved though a deflagration of a press filled granular explosive, which gives larger and more appropriate fragments compared to ordinary ammunition, which detonates. To control the time for the delayed action of the explosive/ fragments due to impact, the sensitivity of the explosive is important to control both experimentally and numerically. In this article we present a small-scale gap test experiment that is developed to study the sensitivity of the explosives. The experimental set up is rather easy and cheap. We show that the sensitivity of the different explosives is very different. We also show that the shock sensitivity is uncorrelated with standard Bam fall hammer and friction tests.