SEARCH · Engineering Papers

Results for “EXPLOSION”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50

All sources NASA NTRS DOE OSTI

DOE OSTI2013

Insensitive explosive composition and method of fracturing rock using an extrudable form of the composition

Insensitive explosive compositions were prepared by reacting di-isocyanate and/or poly-isocyanate monomers with an explosive diamine monomer. Prior to a final cure, the compositions are extrudable. The di-isocyanate monomers tend to produce tough, rubbery materials while polyfunctional monomers (i.e. having more than two isocyanate groups) tend to form rigid products. The extrudable form of the composition may be used in a variety of applications including rock fracturing.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2014

Thin-layer chromatography and colorimetric analysis of multi-component explosive mixtures

A thin-layer chromatography method for detection and identification of common military and peroxide explosives in samples includes the steps of provide a reverse-phase thin-layer chromatography plate; prepare the plate by marking spots on which to deposit the samples by touching the plate with a marker; spot one micro liter of a first standard onto one of the spots, spot one micro liter of a second standard onto another of the spots, and spot samples onto other of spots producing a spotted plate; add eluent to a developing chamber; add the spotted plate to the developing chamber; remove the spotted plate from the developing chamber producing a developed plate; place the developed plate in an ultraviolet light box; add a visualization agent to a dip tank; dip the developed plate in the dip tank and remove the developed plate quickly; and detect explosives by viewing said developed plate.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2015

Explosive bulk charge

An explosive bulk charge, including: a first contact surface configured to be selectively disposed substantially adjacent to a structure or material; a second end surface configured to selectively receive a detonator; and a curvilinear side surface joining the first contact surface and the second end surface. The first contact surface, the second end surface, and the curvilinear side surface form a bi-truncated hemispherical structure. The first contact surface, the second end surface, and the curvilinear side surface are formed from an explosive material. Optionally, the first contact surface and the second end surface each have a substantially circular shape. Optionally, the first contact surface and the second end surface consist of planar structures that are aligned substantially parallel or slightly tilted with respect to one another. The curvilinear side surface has one of a smooth curved geometry, an elliptical geometry, and a parabolic geometry.

02 PETROLEUM↗

DOE OSTI2015

Insensitive explosive composition and method of fracturing rock using an extrudable form of the composition

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

DOE OSTI2018

Gas Retention in an HMX-based Explosive (LX-14)

In previous studies, we found that the nitroplasticizer in the HMX-based explosive PBX 9501 played a crucial role in cookoff, especially when predicting response in larger systems. We have recently completed experiments with a similar explosive, LX-14, that has a relatively nonreactive binder. We expected the ignition times for LX-14 to be longer than PBX 9501 since PBX 9501 has a more reactive binder. However, our experiments show the opposite trend. This paradox can be explained by retention of reactive gases within the interior of LX-14 by the higher strength binder resulting in faster ignition times. In contrast, the binder in PBX 9501 melts at low temperatures and does not retain decomposition gases as well as the LX- 14 binder. Retention of reactive gases in LX-14 may also explain the more violent response in oblique impact tests when compared to PBX 9501.

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEF↗

DOE OSTI2017

Effect of Geologic Setting on Local Response to Chemical Explosions

Presentation discussed the effect of geologic setting on local response to chemical explosions using six chemical explosive tests of varying yield-scaled depth-of-burial as part of the Source Physics Experiment series at the Nevada National Security Site.

58 GEOSCIENCES↗

DOE OSTI2019

Multi-phasic explosive fracturing system

Disclosed herein are embodiments of precursor components (or compositions thereof) that can be combined with one or more additional components (or compositions thereof) to form an explosive composition. The disclosed precursor components (or compositions thereof) can be handled and transported safely to a particular location where they can be mixed with liquid fuel to form an explosive composition. In particular disclosed embodiments, the precursor components (or compositions thereof) can comprise, consist essentially of, or consist of an oxidizer component, a metal component, or combinations thereof.

02 PETROLEUM↗

DOE OSTI2023

Mechanical and thermomechanical properties of an LLM-105 based PBX high explosive with and without accelerated aging

In this paper we present measurements and analysis on the mechanical and thermomechanical properties of the LLM-105 based plastic bonded high explosive RX-55-DQ. Specifically we present uni-axial compression, and thermal measurements (CTE and ratchet growth), and for some of the measurements we provide a comparison to measurements on TATB-based PBX 9502. We also present the same mechanical property measurements performed on RX-55-DQ samples that underwent accelerated aging.

thermomechnical properties↗

DOE OSTI2016

Noble Gas Migration Experiment to Support the Detection of Underground Nuclear Explosions

A Noble Gas Migration Experiment (NGME) funded by the National Center for Nuclear Security and conducted at the Nevada National Security Site (NNSS) in collaboration with Lawrence Livermore national Laboratory and National Security Technology provided critical on-site inspection (OSI) information related to the detection of an underground nuclear explosion (UNE) event using noble gas signatures.

Underground nuclear explosion, Explosion cavity, O↗

DOE OSTI2019

Investigation on Microstructure and Mechanical Properties of TA10–Q245R Composite Plate Formed by Explosive Welding

The titanium alloy TA10 and the carbon steel Q245R are welded by explosive welding, and post-weld heat treatment (PWHT) is carried out for the TA10–Q245R composite plate. Microstructure and mechanical properties of the composite plate are investigated both in as-welded (AW) condition and after PWHT, respectively. Results show that, in AW condition, the bonding interface of composite plate presents wavy morphology, and at both sides of the interface plastic deformation is generated to a certain degree. Near the interface interdiffusion zone of alloying elements exists, and no Fe-Ti intermetallic compound is produced at the interface. SEM images indicate that the tensile fracture of composite plate presents the characteristic of ductile fracture, and no defects such as gas pores or impurities are found on the surface of shear fracture. After PWHT, the interfacial microstructure of the composite plate is obviously changed. Compared with the mechanical properties of the composite plate in AW condition, both tensile strength and shear strength of the composite plate are decreased to a certain extent after PWHT. With various factors into consideration, the suitable heat treatment procedure of TA10–Q245R composite plate is determined as follows: 550 °C × 1.5 h.

36 MATERIALS SCIENCE↗

DOE OSTI2014

Multistage reaction pathways in detonating high explosives

Atomistic mechanisms underlying the reaction time and intermediate reaction products of detonating high explosives far from equilibrium have been elusive. This is because detonation is one of the hardest multiscale physics problems, in which diverse length and time scales play important roles. Here, large spatiotemporal-scale reactive molecular dynamics simulations validated by quantum molecular dynamics simulations reveal a two-stage reaction mechanism during the detonation of cyclotrimethylenetrinitramine crystal. Rapid production of N{sub 2} and H{sub 2}O within ∼10 ps is followed by delayed production of CO molecules beyond ns. We found that further decomposition towards the final products is inhibited by the formation of large metastable carbon- and oxygen-rich clusters with fractal geometry. In addition, we found distinct unimolecular and intermolecular reaction pathways, respectively, for the rapid N{sub 2} and H{sub 2}O productions.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2015

In-situ Raman spectroscopy and high-speed photography of a shocked triaminotrinitrobenzene based explosive

We have developed a single-shot Raman spectroscopy experiment to study at the molecular level the initiation mechanisms that can lead to sustained detonation of a triaminotrinitrobenzene-based explosive. Shocks up to 30 GPa were generated using a two-stage laser-driven flyer plate generator. The samples were confined by an optical window and shock pressure was maintained for at least 30 ns. Photon Doppler Velocimetry measurements were performed at the explosive/window interface to determine the shock pressure profile. Raman spectra were recorded as a function of shock pressure and the shifts of the principal modes were compared to static high-pressure measurements performed in a diamond anvil cell. Our shock data indicate the role of temperature effects. Our Raman spectra also show a progressive extinction of the signal which disappears around 9 GPa. High-speed photography images reveal a simultaneous progressive darkening of the sample surface up to total opacity at 9 GPa. Reflectivity measurements under shock compression show that this opacity is due to a broadening of the absorption spectrum over the entire visible region.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2016

Compaction shock dissipation in low density granular explosive

The microstructure of granular explosives can affect dissipative heating within compaction shocks that can trigger combustion and initiate detonation. Because initiation occurs over distances that are much larger than the mean particle size, homogenized (macroscale) theories are often used to describe local thermodynamic states within and behind shocks that are regarded as the average manifestation of thermodynamic fields at the particle scale. In this paper, mesoscale modeling and simulation are used to examine how the initial packing density of granular HMX (C{sub 4}H{sub 8}N{sub 8}O{sub 8}) C{sub 4}H{sub 8}N{sub 8}O{sub 8} having a narrow particle size distribution influences dissipation within resolved, planar compaction shocks. The model tracks the evolution of thermomechanical fields within large ensembles of particles due to pore collapse. Effective shock profiles, obtained by averaging mesoscale fields over space and time, are compared with those given by an independent macroscale compaction theory that predicts the variation in effective thermomechanical fields within shocks due to an imbalance between the solid pressure and a configurational stress. Reducing packing density is shown to reduce the dissipation rate within shocks but increase the integrated dissipated work over shock rise times, which is indicative of enhanced sensitivity. In all cases, dissipated work is related to shock pressure by a density-dependent power law, and shock rise time is related to pressure by a power law having an exponent of negative one.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2026

The effect of dogbone sample size in the tensile testing of TATB-based plastic‑bonded explosive materials

Mechanical properties are of interest for many plastic‑bonded explosive (PBX) materials with tensile properties being of particular interest. Direct tensile measurements using dogbone-shaped samples are considered the gold standard, but they are fairly large, making testing more costly and less desirable from a safety perspective. We investigated whether the measured tensile strength depends on the dogbone specimen size, which to our knowledge, has not been reported in the literature for PBX materials. Understanding this should inform the feasibility of employing smaller samples and how sample size should be considered when comparing PBX dogbone values in the literature. The TATB-based PBX dogbone sample size was varied by (a) scaling all dimensions proportionally and (b) varying only the length of the samples. It was observed that the measured tensile peak stress (strength) was a function of the sample size, and was more dependent on the diameter (cross-sectional area) than the length of the samples. Since peak stress is calculated as peak force normalized to the diameter of the sample, one might not expect an explicit diameter dependence for the peak stress. Therefore, these results suggest there may be an additional strengthening effect as the sample diameter is increased.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2016

Dimensionality effects in void-induced explosive sensitivity

Here, the dimensionality of defects in high explosives controls their heat generation and the expansion of deflagrations from them. We compare the behaviour of spherical voids in three dimensions to that of circular voids in two dimensions. The behaviour is qualitatively similar, but the additional focusing along the extra transverse dimension significantly reduces the piston velocity needed to initiate reactions. However, the reactions do not grow as well in three dimensions, so detonations require larger piston velocities. Pressure exponents are seen to be similar to those for the two-dimensional system.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2013

THE GALACTIC SUPERNOVA REMNANT W49B LIKELY ORIGINATES FROM A JET-DRIVEN, CORE-COLLAPSE EXPLOSION

We present results from a 220 ks observation of the Galactic supernova remnant (SNR) W49B using the Advanced CCD Imaging Spectrometer on board the Chanrda X-ray Observatory. We exploit these data to perform detailed spatially resolved spectroscopic analyses across the SNR with the aim to investigate the thermodynamic properties and explosive origin of W49B. We find substantial variation in the electron temperature and absorbing column toward W49B, and we show that the mean metal abundances are consistent with the predicted yields in models of bipolar/jet-driven core-collapse SNe. Furthermore, we set strict upper limits on the X-ray luminosity of any undetected point sources, and we exclude the presence of a neutron star associated with W49B. We conclude that the morphological, spectral, and environmental characteristics of W49B are indicative of a bipolar Type Ib/Ic SN origin, making it the first of its kind to be discovered in the Milky Way.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2013

A 10,000 YEAR OLD EXPLOSION IN DR21

Sensitive high angular resolution ({approx}2'') CO(2-1) line observations made with the Submillimeter Array of the flow emanating from the high-mass star-forming region DR21 located in the Cygnus X molecular cloud are presented. These new interferometric observations indicate that this well known enigmatic outflow appears to have been produced by an explosive event that took place about 10,000 years ago, and that might be related to the disintegration of a massive stellar system such as the one that occurred in Orion Becklin-Neugebauer/Kleinman-Low 500 years ago, but about 20 times more energetic. This result therefore argues in favor of the idea that the disintegration of young stellar systems perhaps is a frequent phenomenon present during the formation of massive stars. However, many more theoretical and observational studies are still needed to confirm our hypothesis.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2016

THE OXYGEN FEATURES IN TYPE Ia SUPERNOVAE AND IMPLICATIONS FOR THE NATURE OF THERMONUCLEAR EXPLOSIONS

The absorption feature O i λ 7773 is an important spectral indicator for type Ia supernovae (SNe Ia) that can be used to trace the unburned material in outer layers of the exploding white dwarf (WD). In this work, we use a large sample of SNe Ia to examine this absorption at early phases (i.e., 13 day ≲ t ≲ 7 day) and make comparisons with the absorption features of Si ii λ 6355 and the Ca ii near-infrared triplet. We show that for a subgroup of spectroscopically normal SNe with normal photospheric velocities (i.e., v {sub si} ≲ 12,500 km s{sup 1} at optical maximum), the line strength of the high velocity feature (HVF) of O i is inversely correlated with that of Si ii (or Ca ii), and this feature also shows a negative correlation with the luminosity of SNe Ia. This finding, together with other features we find for the O i HVF, reveal that for this subgroup of SNe Ia, explosive oxygen burning occurs in the outermost layer of the SN. Differences in the oxygen burning could lead to the observed diversity, which is in remarkable agreement with the popular delayed-detonation model of Chandrasekhar mass WDs.

79 ASTRONOMY AND ASTROPHYSICS↗