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Propagation studies of metastable intermolecular composites (MIC).

Description: Thermite materials are attractive energetic materials because the reactions are highly exothermic, have high energy densities, and high temperatures of combustion. However, the application of thermite materials has been limited because of the relative slow release of energy compared to other energetic materials. Engineered nano-scale composite energetic materials, such as Al/MoO{sub 3}, show promise for additional energetic material applications because they can react very rapidly. The composit… more
Date: January 1, 2002
Creator: Son, S. F.; Busse, J. R.; Asay, B. W.; Peterson, P. D.; Mang, J. T.; Bockmon, B. et al.
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Partner: UNT Libraries Government Documents Department
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Modeling DDT in granular explosives with a multi-dimensional hydrocode

Description: We describe results obtained with the implementation of a new large drag limit, two-phase continuum mixture model of DDT into MESA2D. The kinetics scheme originally described by BN is used to simulate a suite of 1D and 2D experiments. The BN kinetics scheme is found to be inadequate.
Date: September 1, 1995
Creator: Kober, E. M.; Bdzil, J. B. & Son, S. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Engineering models of deflagration-to-detonation transition

Description: For the past two years, Los Alamos has supported research into the deflagration-to-detonation transition (DDT) in damaged energetic materials as part of the explosives safety program. This program supported both a theory/modeling group and an experimentation group. The goal of the theory/modeling group was to examine the various modeling structures (one-phase models, two-phase models, etc.) and select from these a structure suitable to model accidental initiation of detonation in damaged explos… more
Date: July 1995
Creator: Bdzil, J. B. & Son, S. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Some Observations on the Structure of TATB

Description: The recent discovery of second-harmonic light generation (SHG) from 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) has renewed interest in both the crystallography and the identification of defect structures in this material. The accepted crystal structure is triclinic but centrosymmetric (P-1); SHG is not expected from materials of this symmetry. A wide variety of syntheses have been shown to produce SHG-positive materials, including an emulsion technique, two different recrystallization methods,… more
Date: June 28, 1999
Creator: Phillips, D. S.; Schwarz, R. B.; Skidmore, C. B.; Hiskey, M. A. & Son, S. F.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Steady state HNG combustion modeling

Description: Two simplified modeling approaches are used to model the combustion of Hydrazinium Nitroformate (HNF, N{sub 2}H{sub 5}-C(NO{sub 2}){sub 3}). The condensed phase is treated by high activation energy asymptotics. The gas phase is treated by two limit cases: the classical high activation energy, and the recently introduced low activation energy approach. This results in simplification of the gas phase energy equation, making an (approximate) analytical solution possible. The results of both models… more
Date: April 1, 1998
Creator: Louwers, J.; Gadiot, G. M. H. J. L.; Brewster, M. Q.; Son, S. F.; Parr, T. & Hanson-Parr, D.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Deflagration to detonation experiments in granular HMX

Description: In this paper the authors report on continuing work involving a series of deflagration-to-detonation transition (DDT) experiments in which they study the piston-initiated DDT of heavily confined granular cyclotetramethylenetetranitramine (HMX). These experiments were designed to he useful in model development and evaluation. A main focus of these experiments is the effect of density on the DDT event. Particle size distribution and morphology are carefully characterized. In this paper they prese… more
Date: March 1, 1998
Creator: Burnside, N. J.; Son, S. F.; Asay, B. W. & Dickson, P. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Characterization of HMX particles in PBX 9501

Description: The particle size distribution and morphology of HMX (cyclotetramethylene-tetranitramine) in the plastic-bonded explosive, PBX 9501 (95% HMX and 5% polymeric binder, by weight), are important to understanding the micromechanical behavior of this material. This paper shows that the size distribution of the {open_quotes}as-received{close_quotes} HMX powder, as measured by light scattering, is not preserved through the processing operations of formulation into molding powder and subsequent consoli… more
Date: September 1, 1997
Creator: Skidmore, C. B.; Phillips, D. S.; Son, S. F. & Asay, B. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Remote plunger removal device for small-scale incremental pressing

Description: Small-scale pressing of high explosives (HE) at Los Alamos National Laboratory (LANL) and elsewhere is routinely performed using pneumatic presses. Blast shields provide protection to the operator during the pressing procedure, but safety of the operator is a concern during removal of the plunger, which is currently performed manually. To minimize this risk, very high tolerances between the plunger and the die are required. These tolerances are often very costly, especially in the case of long,… more
Date: September 1, 1997
Creator: Burnside, N.J.; Son, S.F. & Asay, B.W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Modeling energy dissipation induced by quasi-static compaction of granular HMX

Description: A simple extension of a conventional two-phase (inert gas and reactive solid) continuum model of Deflagration-to-Detonation Transition (DDT) in energetic granular material is given to account for energy dissipation induced by quasi-static compaction. To this end, the conventional model equations,, valid in the limit of negligible gas phase effects, are supplemented by a relaxation equation governing irreversible changes in solid volume fraction due to intergranular friction, plastic deformation… more
Date: November 1, 1997
Creator: Gonthier, K.A.; Menikoff, R.; Son, S.F. & Asay, B.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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New paradigm for simplified combustion modeling of energetic solids: Branched chain gas reaction

Description: Two combustion models with simple but rational chemistry are compared: the classical high gas activation energy (E{sub g}/RT {much_gt} 1) Denison-Baum-Williams (DBW) model, and a new low gas activation energy (E{sub g}/RT {much_lt} 1) model recently proposed by Ward, Son, and Brewster (WSB). Both models make the same simplifying assumptions of constant properties, Lewis number unity, single-step, second order gas phase reaction, and single-step, zero order, high activation energy condensed phas… more
Date: September 1, 1997
Creator: Brewster, M. Q.; Ward, M. J. & Son, S. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A model for steady-state HNF combustion

Description: A simple model for the combustion of solid monopropellants is presented. The condensed phase is treated by high activation energy asymptotics. The gas phase is treated by two limit cases: high activation energy, and low activation energy. This results in simplification of the gas phase energy equation, making an (approximate) analytical solution possible. The results of the model are compared with experimental results of Hydrazinium Nitroformate (HNF) combustion.
Date: September 1, 1997
Creator: Louwers, J.; Gadiot, G.M.H.J.L.; Brewster, M.Q. & Son, S.F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Aging and PBX 9502

Description: Components made from PBX 9502, an insensitive high explosive formulated with triaminotrinitrobenzene (TATB) and Kel-F 800 binder, have been in service for nearly two decades. Since that time, samples have been destructively evaluated to determine if potential changes that might affect safety, reliability, or performance have occurred in the high explosive with time. Data from routine, historical testing is reported elsewhere. This paper focuses on specific tests conducted to evaluate the effect… more
Date: December 31, 1998
Creator: Skidmore, C. B.; Idar, D. J.; Buntain, G. A.; Son, S. F. & Sander, R. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Modeling compaction-induced energy dissipation of granular HMX

Description: A thermodynamically consistent model is developed for the compaction of granular solids. The model is an extension of the single phase limit of two-phase continuum models used to describe Deflagration-to-Detonation Transition (DDT) experiments. The focus is on the energetics and dissipation of the compaction process. Changes in volume fraction are partitioned into reversible and irreversible components. Unlike conventional DDT models, the model is applicable from the quasi-static to dynamic com… more
Date: December 31, 1998
Creator: Gonthier, K.A.; Menikoff, R.; Son, S.F. & Asay, B.W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ignition dynamics of high explosives

Description: Mechanical insults of granular high explosives (HE) can result in localized areas of elevated temperature, or hot spots. The evolution of these hot spots is a central issue of HE science. Because of the complexity involved, it is worthwhile to study mechanical and reaction processes in isolation. Mechanical processes are isolated and studied using inert materials or weak insults where reaction may be minimal. Likewise, purely thermal processes can be considered to isolate HE reaction response. … more
Date: December 31, 1998
Creator: Ali, A. N.; Son, S. F.; Sander, R. K. & Asay, B. W.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Ignition dynamics of high explosives

Description: The laser ignition of the explosives HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine, C{sub 4}H{sub 8}N{sub 8}O{sub 8}), {delta}-phase HMX, PBX 9501 (95% HMX, 2.5% Estane, 2.5% BDNPA/BDNPF), TATB (1,3,5-triamino-2,4,6-trinitrobenzene, C{sub 6}H{sub 6}N{sub 6}O{sub 6}), and PBX 9502 (95% TATB, 5% Kel-F) and aged PBX 9502 has been conducted with the intent to compare the relative sensitivities of those explosives and to investigate the effect of beam profile, binder addition, and porosity. … more
Date: April 1, 1999
Creator: Ali, A. N.; Son, S. F.; Sander, R. K.; Asay, B. W. & Brewster, M. Q.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Inert plug formation in the DDT of granular energetic materials

Description: A mechanism is proposed to explain the {open_quotes}plugs{close_quotes} that have been observed in deflagration-to-detonation transition (DDT) of granular explosives. Numerical simulations are performed that demonstrate the proposed mechanism. Observed trends are reproduced.
Date: September 1, 1995
Creator: Son, S.F.; Asay, B.W. & Bdzil, J.B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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