Energetic Material Detonation Characterization: A Laboratory‐Scale Approach

Abstract

A novel energetic‐material detonation and air‐blast characterization technique is proposed through the use of a laboratory‐scale‐based modified “aquarium test.” A streak camera is used to record the radial shock wave expansion rate at the energetic materialair interface of spherical laboratory‐scale (i.e., gram‐range) charges detonated in air. A linear regression fit is applied to the measured streak record data. Using this in conjunction with the conservation laws, material Hugoniots, and two empirically established relationships, a procedure is developed to determine fundamental detonation properties (pressure, velocity, particle velocity, and density) and air shock wave properties (pressure, velocity, particle velocity, and density) at the energetic materialair interface. The experimentally determined properties are in good agreement with published values. The theory’s applicability is extended using historical experimental test data due to the limited number of experiments able to be performed. Predicted detonation wave and air shock wave properties are in good agreement for a multitude of energetics across various atmospheric conditions.

Laboratory‐Scale Method for Estimating Explosive Performance from Laser‐Induced Shock Waves

“…Estimated detonationv elocities for conventional energetic materials based on the measured characteristic laser-induced shock velocities differ from values obtained through large-scale detonative testing by less than 1% for pure explosives and less than 5% for explosivef ormulations. LASEM is ap otential pre-screening toolf or the development of new energetic materials and formulations prior to small-scale detonation testing [35].L ASEM will be particularly useful in several situations:w hen candidate materials are only available in limited quantities (and scale-up is costly or time-consuming);f or energetic materials with al arger critical diameter (e.g.,i nsensitive formulations) where small-scale detonative testing [10,11]i sn ot possible; or for materials thatr equire non-conventional means to induce detonation.C urrentl imitations of the technique include the lack of information about the critical diametero r sensitivity of the material and the inability to determine if the material can be detonated using conventional methods. The applicability of LASEM to non-conventional energetic materials is still under investigation.…”

“…In addition to the challenging experimental conditions, conventional detonationt esting methods require grams of explosive, e.g., the sand [4],f ragmentation [4],l ead block [5],b allistic mortar [4,5],p late dent [ 4,6,7],r ate stick [8], cylinder expansion [ 4,9],m odified aquarium [10],o rd isc acceleration experiments [11].S caling-up the synthesis of new energetic materials to gram quantities is expensive and resource-limited, thus many potential candidate materials are never fully tested.Ap re-screening testc apable of estimating the large-scale detonation performance of energetic materials using only milligram quantities of material would significantly decrease the development time for new explosives.…”

Ultra‐High Fidelity Laser‐Induced Air Shock from Energetic Materials

“…Central to the analysis of optical-tracking techniques of explosively driven shock waves given by Kleine, Hargather, and Biss [1][2][3][4] is the scalability of an air-blast-wave model from multi-kg to sub-mg charges. In each, the air blast wave was fit to the semi-empirical, spatiotemporal curvefit proposed by Dewey [22,23], as given in Eqn.…”

“…Biss and Settles further expanded upon the work of Hargather and Settles for the characterization of energetic materials requiring a booster charge to initiate a detonation . Later in 2013, air‐blast‐wave characterization of HE was extended by Biss through a modification of the aquarium test, permitting the determination of several key detonation‐performance parameters (detonation velocity, Chapman‐Jouguet pressure, reaction‐products particle velocity, and density) and air‐blast‐performance parameters (peak pressure, particle velocity, and density) from a single experimental measurement of the interface shock wave velocity produced by laboratory‐scale charges (<25 g) detonated in air .…”