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Experimental measurements of the detonation wave profile in a TATB based explosive  [cached]
Bouyer V.,Doucet M.,Decaris L.
EPJ Web of Conferences , 2011, DOI: 10.1051/epjconf/20101000030
Abstract: We report results of the experimental measurements of the detonation wave profile of the TATB based plastic bonded explosive T2 (97 w. % of TATB) using VISAR and Heterodyne Velocimetry (HV – same as Photon Doppler Velocimetry). The experiment consists in initiating a detonation wave in a 15 mm diameter cylinder of explosive using an explosive wire detonator and an explosive booster. In order to obtain the particle velocity history in the reaction zone, we measure particle velocity at the interaction of the detonation front with an aluminized window or the free surface velocity of a metallic foil. Lithium Fluoride (LIF), PMMA and steel have been tested. Several shots have been performed for different lengths of explosive. We compare the VISAR and HV measurements. With LIF and steel, VISAR and HV diagnostics give very similar profiles. The ZND profile obtained on LIF is resolved with both techniques. With PMMA, HV gives a more accurate profile than VISAR in the reaction zone. There is no evidence of the influence of the explosive cylinder length.
Coating and Characterization of Mock and Explosive Materials  [PDF]
Emily M. Hunt,Matt Jackson
Advances in Materials Science and Engineering , 2012, DOI: 10.1155/2012/468032
Abstract: This project develops a method of manufacturing plastic-bonded explosives by using use precision control of agglomeration and coating of energetic powders. The energetic material coating process entails suspending either wet or dry energetic powders in a stream of inert gas and contacting the energetic powder with atomized droplets of a lacquer composed of binder and organic solvent. By using a high-velocity air stream to pneumatically convey the energetic powders and droplets of lacquer, the energetic powders are efficiently wetted while agglomerate drying begins almost immediately. The result is an energetic powder uniformly coated with binder, that is, a PBX, with a high bulk density suitable for pressing. Experiments have been conducted using mock explosive materials to examine coating effectiveness and density. Energetic materials are now being coated and will be tested both mechanically and thermally. This allows for a comprehensive comparison of the morphology and reactivity of the newly coated materials to previously manufactured materials. 1. Introduction The study of explosives is of considerable importance because of their many technological and defense-related applications. Plastic-bonded explosives (PBXs) are a mixture of particulate energetic material and a polymer binder. PBXs have been commonly used in both military and industry because of their improved safety, enhanced mechanical properties, and reduced vulnerability during storage and transportation [1]. Mechanical initiation of PBXs is strongly dependent on the heterogeneity of the energetic materials and polymeric binder at the mesoscale [2, 3]. The polymer binder in the PBXs plays an important role in enhancing the properties of the base explosive (i.e., improving mechanical properties, enhancing chemical and thermal stability, reducing environmental impact, etc.). Therefore, there is an increasing need to understand and predict the chemical, thermal, and mechanical properties of the PBXs as well as the interactions among the energetic particles and polymeric binder [4]. Although many studies have been conducted on composite explosives to examine the effects of such parameters as particle size [5], crystal defects [6], and binder properties [7], the contributions of grain anisotropy, defects and interfacial responses to hot-spot initiation still remain very difficult task. This study examines a method to develop PBX in which explosive powder is bound together in a matrix using small quantities (typically 5–10% by weight) of a synthetic polymer or plastic. PBXs are normally used for
VISCO-PLASTIC CONSTITUTIVE MODEL FOR UNIAXIAL AND MULTIAXIAL RATCHETING AT ELEVATED TEMPERATURES
GZKang,QGao,JZhang,
G.Z.Kang
,Q.Gao,J.Zhang

金属学报(英文版) , 2004,
Abstract: Based on the experimental results of the ratcheting for SS304 stainless steel, a new visco-plastic cyclic constitutive model was established to describe the uniaxial and multiaxial ratcheting of the material at room and elevated temperatures within the framework of unified visco-plasticity. In the model, the temperature dependence of the ratcheting was emphasized, and the dynamic strain aging occurred in the temperature range of 400-600℃ for the material was taken into account particularly. Finally, the prediction capability of the developed model was checked by comparing to the corresponding experimental results.
Effective elastic moduli of polymer bonded explosives from finite element simulations  [PDF]
Biswajit Banerjee
Physics , 2005,
Abstract: Finite element analysis has been used successfully to estimate the effective properties of many types of composites. The prediction of effective elastic moduli of polymer-bonded explosives provides a new challenge. These particulate composites contain extremely high volume fractions of explosive particles ($>$ 0.90). At room temperature and higher, the Young's modulus of the particles can be 20,000 times that of the binder. Under these conditions, rigorous bounds and analytical approximations for effective elastic properties predict values that are orders of magnitude different from the experimental values. In this work, an approach is presented that can be used to predict three-dimensional effective elastic moduli from two-dimensional finite element simulations. The approach is validated by comparison with differential effective medium estimates and three-dimensional finite element simulations.
Simulation investigations in the binding energy and mechanical properties of HMX-based polymer-bonded explosives
Jijun Xiao,Guoyong Fang,Guangfu Ji,Heming Xiao
Chinese Science Bulletin , 2005, DOI: 10.1360/982004-147
Abstract: The molecular simulations of the well-known high explosive β-HMX (cyclotetramethylene tetranitramine) and its fluorine containing polymer-bonded explosives (PBXs) were carried out with the combination method of quantum mechanics, molecular mechanics and molecular dynamics. The atomic cluster model, containing the β-HMX molecule and the polymer molecule whose chain dimension was about the same as β-HMX’s, was fully optimized by AM1 and PM3 semi-empirical molecular orbital and molecular mechanical methods using COMPASS and PCFF force field. Then the calculated binding energy is found to be linearly correlated to each other. Molecular dynamics simulations using COM-PASS force field were performed for β-HMX crystal and the PBXs involving β-HMX and a series of fluorine containing polymers. Their elastic coefficients, moduli and Poisson’s ratios were calculated. It is found that the mechanical properties of β-HMX can be effectively improved by blending with fluorine containing polymers in small amounts.
Simulation investigations in the binding energy and mechanical properties of HMX-based polymer-bonded explosives
Jijun Xiao,Guoyong Fang,Guangfu Ji,Heming Xiao,
XIAOJijun
,FANGGuoyong,JIGuangfu,XIAOHeming

科学通报(英文版) , 2005,
Abstract: The molecular simulations of the well-known high explosive β-HMX (cyclotetramethylene tetranitramine) and its fluorine containing polymer-bonded explosives (PBXs) were carried out with the combination method of quantum mechanics, molecular mechanics and molecular dynamics. The atomic cluster model, containing the β-HMX molecule and the polymer molecule whose chain dimension was about the same as β-HMX’s, was fully optimized by AM1 and PM3 semi-empirical molecular orbital and molecular mechanical methods using COMPASS and PCFF force field. Then the calculated binding energy is found to be linearly correlated to each other. Molecular dynamics simulations using COM-PASS force field were performed for β-HMX crystal and the PBXs involving β-HMX and a series of fluorine containing polymers. Their elastic coefficients, moduli and Poisson’s ratios were calculated. It is found that the mechanical properties of β-HMX can be effectively improved by blending with fluorine containing polymers in small amounts.
Experimental results and constitutive modelling for tungsten and tantalum at high strain rates and very high temperatures  [PDF]
G. P. Skoro,J. R. J. Bennett,T. R. Edgecock
Physics , 2011,
Abstract: Recently reported results of the high strain rates, high temperature measurements of the yield stress of tungsten and tantalum have been analyzed. The highest temperature reached in the experiment, based on heating and stressing a thin wire by a fast, high current pulse, was 2520 K and 2720 K, for tantalum and tungsten, respectively. The strain-rates in both the tungsten and tantalum tests were in the range from 500 to 1500 1/s. The parameters for the constitutive equation developed by Zerilli and Armstrong have been determined from the experimental data and the results have been compared with the data obtained at lower temperatures.
HOT DIPPING ALUMINIZED COATING AS HYDROGEN PERMEATION BARRIER
ZYYao,MChini,AAiello,Benamati,
Z. Y Yao
,M. Chini,A. Aiello and G. Benamati

金属学报(英文版) , 2001,
Abstract: The hydrogen permeation experiment of MA NET II with hot dipping aluminized coating was performed in temperature range of 573 to 623K, in gas phase and in liquid Pb-17Li phase. The hydrogen permeation reduction factor (PRP) evaluated in gas phase is 620 at 573K and 260 at 623K, and in liquid Pb-17Li phase is 24-45 at 573K and P2-30 at 623K. The self-healing of coating is obvious and effective above 673K. The pressure dependence of permeation flux indicates strong surface contribution. The way of filling hydrogen by continuous flow and/or bubble can increase permeation flux. The result of SEM-EDS shows that the microcrack is on the surface of the wetted part, but not on the not wetted part. The crack is superficial and affects only thin outside layer not penetrate aluminized layer. The surface elemental analysis shows that Al/O atomic ratio changes from 2/3 of not wetted part to about 1 of wetted part. The damage of coating surface seems to be related to the interaction of outside layer with liquid Pb-17Li and thermal stress during heating sample.
Explosive nucleosynthesis  [PDF]
M. Hernanz
Physics , 2001,
Abstract: Many radioactive nuclei relevant for gamma-ray astrophysics are synthesized during explosive events, such as classical novae and supernovae. A review of recent results of explosive nucleosynthesis in these scenarios is presented, with a special emphasis on the ensuing gamma-ray emission from individual nova and supernova explosions. The influence of the dynamic properties of the ejecta on the gamma-ray emission features, as well as the still remaining uncertainties in nova and supernova models is also reviewed.
Explosive Ising  [PDF]
Sebastian Angst,Silvio R. Dahmen,Haye Hinrichsen,Alfred Hucht,Martin P. Magiera
Statistics , 2012, DOI: 10.1088/1742-5468/2012/06/L06002
Abstract: We study a two-dimensional kinetic Ising model with Swendsen-Wang dynamics, replacing the usual percolation on top of Ising clusters by explosive percolation. The model exhibits a reversible first-order phase transition with hysteresis. Surprisingly, at the transition flanks the global bond density seems to be equal to the percolation thresholds.
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