Harry Brandt

Bio: Harry Brandt is an academic researcher from University of California, Davis. The author has contributed to research in topics: Detonation & Explosive material. The author has an hindex of 1, co-authored 2 publications receiving 5 citations.

Detonation Properties of 1,3,5‐Triamino‐2,4,6‐Trinitrobenzene when impacted by hypervelocity projectiles

Abstract: This investigation analyzes the reaction of an insensitive high explosive with binder to hypervelocity impact by four projectiles of two types: rod and plate. The insensitive high explosive is composed of 92.5% 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) and 7.5% Kel-F 800 binder, a vinylidene fluoride-chlorotrifluoroethylene copolymer. In this paper, for simplicity, we refer to this composition as “TATB”. Of the the impacting projectiles, three are steel-rod assemblies ranging in weight from 32.6 g to 34.6 g, and are composed of a steel rod 8 mm in diameter and 19 mm in length, of which 9 mm protrudes from a Polyzelux plastic holder. The fourth is a tantalum-plate assembly, weighing 23.9 grams and composed of a tantalum plate 24.2 mm in diameter and 1.5 mm in thickness mounted on a Polyzelux holder. The tantalum-plate experiment provides a highly efficient diverging detonation profile as predicted by similar previous investigations with flyer plates and TATB. The steel-rod experiments are compared to the tantalum-plate experiment to determine if detonation has occurred with the steel-rod impacts. The projectiles are accelerated by a two-stage, light-gas gun to velocities in the range of 3.1 km/s to 6.5 km/s (10,171 ft/s to 21,325 ft/s) and have bracketed the detonation threshold of the impacted TATB target. Comparisons of the TATB reaction data to a computer modeling of the experiment show that at 3.06 km/s, the computer model correctly predicts no initiation of detonation; at 4.75 km/s, the computer model correctly predicts a partial detonation; and at 5.67 km/s and 6.53 km/s, both the computer analyses and the experiments give divergent detonations.

The Effect of Radial Confinement of Explosive on the Impulse delivered to an explosively driven circular plate

Abstract: The effect of radial confinement of explosive on the impulse delivered to an explosively driven circular plate was investigated numerically. The results are applicable to the design of explosively formed penetrators. Aluminum radial confinement and additional radial explosive were investigated as means of increasing the impulse delivered to the plate. The radial thicknesses were varied from 0% to 10% of the explosive charge diameter with copper plates having thicknesses of 2%, 5% and 8% of the explosive charge diameter. Results show the use of radial confinement to be more effective with thicker plates. The increase in impulse provided by aluminum confinement was as great as 18% with an 8% charge diameter thick plate, compared to 12% with a 2% charge diameter thick plate. Regardless of the plate thickness, additional radial explosive can be more effective than aluminum radial confinement in increasing the impulse. For example a 10% charge diameter thickness of explosive increases the impulse by up to 28%, compared to 18% for the same thickness of aluminum. The results do not exhibit dependence on the method of detonation, nor on the length of the explosive charge.

The insensitive high explosive triaminotrinitrobenzene (TATB): Development and characterization, 1888 to 1994

Abstract: Assembled in this report are data and references on TATB and its formulations from its first synthesis in 1888 to 1994. This compilation includes sections on synthesis and preparation, analytical methods, properties, performance, aging and compatibility, and on safety. The information is arranged in chronological order within each section. A bibliography rounds out the report.

Changes in Pore Size Distribution upon Thermal Cycling of TATB‐based Explosives Measured by Ultra‐Small Angle X‐Ray Scattering

Abstract: Hot-spot models of initiation and detonation show that voids or porosity ranging from nanometer to micrometer in size within highly insensitive energetic materials affect initiability and detonation properties. Thus, the knowledge of the void size distribution, and how it changes with the volume expansion seen with temperature cycling, are important to understanding the properties of the insensitive explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). In this paper, void size distributions in the 2 nm to 2 μm regime, obtained from small-angle X-ray scattering measurements, are presented for LX-17-1, PBX-9502, and ultra-fine TATB formulations, both as processed and after thermal cycling. Two peaks were observed in the void size distribution: a narrow peak between 7–10 nm and a broad peak between 20 nm and about 1 mm. The first peak was attributed to porosity intrinsic to the TATB crystallites. The larger pores were believed to be intercrystalline, a result of incomplete consolidation during processing and pressing. After thermal cycling, these specimens showed an increase in both the number and size of these larger pores. These results illuminate the nature of the void distributions in these TATB-based explosives from 2 nm to 2 μm and provide empirical experimental input for computational models of initiation and detonation.

Chemical Explosives and Rocket Propellants

Abstract: Without explosives we probably would still be riding around in horse-drawn carriages; yet when most people think of explosives, they think only of bombs and artillery shells used in warfare. It appears, however, that more explosives have been used in industry for peaceful purposes than in all the wars put together.1,2 According to U.S. Bureau of Mines reports, industrial consumption of explosives in the United States alone totaled nearly 110 billion lb from 1912 through 1989.3 Industrial explosives are currently being produced in the United States at a rate of nearly 5 billion lb/year.

Surface characterization of 1,3,5-triamino-2,4,6-trinitrobenzene by X-ray photoelectron spectroscopy and Fourier transform nuclear magnetic resonance

Abstract: X-ray photoelectron spectroscopy (XPS) and Fourier transform nuclear magnetic resonance (FT-NMR) were used to characterize 1,3,5-triamino-2,4,6-trinitrobenzene. The XPS results showed approximately equal signal intensities of N 1s electrons from NO2 and NH2; this agrees well with the theoretically calculated values. An increase in the NH2/NO2 ratio was observed after ultraviolet or X-ray irradiation. FT-NMR at proton frequency showed a characteristic Pake's doublet due to strong proton dipole-dipole interaction in solids. Surface moisture absorption was observed when the samples were exposed to a humid environment. The moisture molecules were found to be partially bonded to the surfaces or diffused into the crystal lattice after an extended exposure period.