Browsing by Author "Clements, Jim"

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    Experimental fragmentation of pipe bombs with varying case thickness
    (Elsevier, 2019-11-05) da Silva, Luciana A.; Johnson, Steve; Critchley, Richard; Clements, Jim; Norris, Karl; Stennett, Christopher
    Among all the improvised explosive devices (IEDs) known, pipe bombs are one of the most popular devices used by terrorists. They are simple to use, easy to construct and materials are readily available. For this IED, fragmentation is the primary injury mechanism, which makes them a desirable weapon for terrorists aiming to inflict maximum human casualties. Although the investigation of fragmentation pattern is not novel, there is limited data available on pipe bombs performance in the open literature. Therefore, this research is looking at validating results in current literature, which showed limited repetition and weak experimental design so far; by trial with six pipe bombs with two different thickness (3 of each). The pipe bombs consisted of mild steel casing and aluminised ammonium nitrate as the explosive filler. Fragments were collected, with an average recovery of 72%, and measured regarding mass and velocity. The experiment results show a correlation between the pipe thickness and both the size and velocity of fragments.
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    Towards understanding the detonation properties of additively manufactured RDX: Dry powder printed
    (Royal Society of Chemistry, 2022-06-22) McGee, Christine; Stennett, Christopher; Clements, Jim; Vrcelj, Ranko
    Research into additive manufacturing (AM) has been steadily expanding over the past five decades. Where once only polymeric materials could be reliably printed, AM has been adapted to print with a range of materials such as biological, metallic, ceramic and even foodstuffs. The advantages of manufacturing in an additive manner include; a) a layer-by-layer approach allows the creation of architecturally complex structures, b) a reduction in weight, c) lessening of waste and d) the ability to create parts that that are otherwise difficult or too costly to produce. 1,3,5-Trinitro-1,3,5-triazinane (RDX) is regularly used in explosive systems. Its detonation properties when conventionally manufactured are widely researched and broadly understood. However, recent advances in additive manufacturing technologies have led to greater interest in utilising RDX in this manner. There is growing evidence that emerging formulations and printing methods are changing the detonation properties of RDX composites, the critical diameter among them.1 This study reports on beginning to understand the detonation properties of additively manufactured RDX via a dry powder printing method.