Shock Desensitization of PBX-9404 and Composition B-3

Shock Desensitization of PBX-9404 and Composition B-3 PDF Author:
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Category :
Languages : en
Pages :

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PBX-9404 and Composition B-3 were desensitized by subjecting them to shocks in the pressure range 10 to 24 kbar. Results show that the collapse of voids, and thus the activation of hot spots by shock waves, takes time and may require more than 5 .mu.s. This time is, in a way, a counterpart of the induction time for shock initiation of a homogeneous explosive. Gittings' data are adduced to extend the results to 100 kbar and to show that at high pressures desensitization occurs in a very brief time window. When the voids have been collapsed, the relatively homogeneous explosive is resistant to detonation through an Arrhenius type of reaction because of the lower shock temperature resulting from double shocking. This conclusion is supported by experiments on single crystals of HMX and by shock temperature calculations. The time required for desensitization of PBX-9404 is related to pressure by the expression p/sup 2.2/tau = 1150. 21 references, 5 figures, 5 tables.

Shock Desensitization of PBX-9404 and Composition B-3

Shock Desensitization of PBX-9404 and Composition B-3 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
PBX-9404 and Composition B-3 were desensitized by subjecting them to shocks in the pressure range 10 to 24 kbar. Results show that the collapse of voids, and thus the activation of hot spots by shock waves, takes time and may require more than 5 .mu.s. This time is, in a way, a counterpart of the induction time for shock initiation of a homogeneous explosive. Gittings' data are adduced to extend the results to 100 kbar and to show that at high pressures desensitization occurs in a very brief time window. When the voids have been collapsed, the relatively homogeneous explosive is resistant to detonation through an Arrhenius type of reaction because of the lower shock temperature resulting from double shocking. This conclusion is supported by experiments on single crystals of HMX and by shock temperature calculations. The time required for desensitization of PBX-9404 is related to pressure by the expression p/sup 2.2/tau = 1150. 21 references, 5 figures, 5 tables.

Preshock Desensitization of PBX Explosives

Preshock Desensitization of PBX Explosives PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
Preshocking delays initiation of PBX-9404 and PBX-9501, relative to unshocked material. In PBX-9404 preshock experiments, a first shock of 2.3 GPa was followed 0.65 [mu]s later by a second shock of 5.6 GPa. In PBX-9501, a preshock of 2.8 GPa and 0.32 us duration was followed by an initiating shock of 6.0 GPA. Both PBX explosives show clear desensitization while the preshock persists. In PBX-9404, initiation of detonation occurs nearly as anticipated for the material, after coalescence of the preshock and main shock into a single wave. Multiple embedded magnetic gauges were used to measure the shock histories. Our data indicates a slightly longer run to detonation than expected, even though a single wave is initiating the material. A slight stress reduction at coalescence, as required by the shock dynamics, may be responsible for the overrun. A reactive waste is clearly evident while the preshock persists. The long run to detonation indicates that this reactive wave is not driving the initiation. A set of four preshock experiments were preformed on PBX-9502, which is unreactive at these pressures, to investigate the shock dynamics of the two waves in the HE.

Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 260

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Numerical Modeling of Explosives and Propellants, Second Edition

Numerical Modeling of Explosives and Propellants, Second Edition PDF Author: Charles L. Mader
Publisher: CRC Press
ISBN: 9780849331497
Category : Technology & Engineering
Languages : en
Pages : 456

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Book Description
Charles Mader, a leading scientist who conducted theoretical research at Los Alamos National Laboratory for more than 30 years, sets a new standard with this reference on numerical modeling of explosives and propellants. This book updates and expands the information presented in the author's landmark work, Numerical Modeling of Detonations, published in 1979 and still in use today. Numerical Modeling of Explosives and Propellants incorporates the considerable changes the personal computer has brought to numerical modeling since the first book was published, and includes new three-dimensional modeling techniques and new information on propellant performance and vulnerability. Both an introduction to the physics and chemistry of explosives and propellants and a guide to numerical modeling of detonation and reactive fluid dynamics, Numerical Modeling of Explosives and Propellants offers scientists and engineers a complete picture of the current state of explosive and propellant technology and numerical modeling. The book is richly illustrated with figures that support the concepts, and filled with tables for quick access to precise data. The accompanying CD-ROM contains computer codes that are the national standard by which modeling is evaluated. Dynamic material properties data files and animation files are also included. There is no other book available today that offers this vital information.

High-Pressure Shock Compression of Solids VI

High-Pressure Shock Compression of Solids VI PDF Author: Yasuyuki Horie
Publisher: Springer Science & Business Media
ISBN: 1461300134
Category : Science
Languages : en
Pages : 361

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Book Description
Both experimental and theoretical investigations make it clear that mesoscale materials, that is, materials at scales intermediate between atomic and bulk matter, do not always behave in ways predicted by conventional theories of shock compression. At these scales, shock waves interact with local material properties and microstructure to produce a hierarchy of dissipative structures such as inelastic deformation fields, randomly distributed lattice defects, and residual stresses. A macroscopically steady planar shock wave is neither plane nor steady at the mesoscale. The chapters in this book examine the assumptions underlying our understanding of shock phenomena and present new measurements, calculations, and theories that challenge these assumptions. They address such questions as: - What are the experimental data on mesoscale effects of shocks, and what are the implications? - Can one formulate new mesoscale theories of shock dynamics? - How would new mesoscale theories affect our understanding of shock-induced phase transitions or fracture? - What new computational models will be needed for investigating mesoscale shocks?

Proceedings

Proceedings PDF Author:
Publisher:
ISBN:
Category : Detonation
Languages : en
Pages : 830

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Numerical Modeling of Explosives and Propellants

Numerical Modeling of Explosives and Propellants PDF Author: Charles L. Mader
Publisher: CRC Press
ISBN: 142005239X
Category : Technology & Engineering
Languages : en
Pages : 539

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Book Description
Major advances, both in modeling methods and in the computing power required to make those methods viable, have led to major breakthroughs in our ability to model the performance and vulnerability of explosives and propellants. In addition, the development of proton radiography during the last decade has provided researchers with a major new experimental tool for studying explosive and shock wave physics. Problems that were once considered intractable – such as the generation of water cavities, jets, and stems by explosives and projectiles – have now been solved. Numerical Modeling of Explosives and Propellants, Third Edition provides a complete overview of this rapidly emerging field, covering basic reactive fluid dynamics as well as the latest and most complex methods and findings. It also describes and evaluates Russian contributions to the experimental explosive physics database, which only recently have become available. This book comes with downloadable resources that contain— · FORTRAN and executable computer codes that operate under Microsoft® Windows Vista operating system and the OS X operating system for Apple computers · Windows Vista and MAC compatible movies and PowerPoint presentations for each chapter · Explosive and shock wave databases generated at the Los Alamos National Laboratory and the Russian Federal Nuclear Centers Charles Mader’s three-pronged approach – through text, computer programs, and animations – imparts a thorough understanding of new computational methods and experimental measuring techniques, while also providing the tools to put these methods to effective use.

Shock Waves Science and Technology Library, Vol. 6

Shock Waves Science and Technology Library, Vol. 6 PDF Author: F. Zhang
Publisher: Springer Science & Business Media
ISBN: 3642229662
Category : Science
Languages : en
Pages : 482

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Book Description
This book, as a volume of the Shock Wave Science and Technology Reference Library, is primarily concerned with the fundamental theory of detonation physics in gaseous and condensed phase reactive media. The detonation process involves complex chemical reaction and fluid dynamics, accompanied by intricate effects of heat, light, electricity and magnetism - a contemporary research field that has found wide applications in propulsion and power, hazard prevention as well as military engineering. The seven extensive chapters contained in this volume are: - Chemical Equilibrium Detonation (S Bastea and LE Fried) - Steady One-Dimensional Detonations (A Higgins) - Detonation Instability (HD Ng and F Zhang) - Dynamic Parameters of Detonation (AA Vasiliev) - Multi-Scaled Cellular Detonation (D Desbordes and HN Presles) - Condensed Matter Detonation: Theory and Practice (C Tarver) - Theory of Detonation Shock Dynamics (JB Bdzil and DS Stewart) The chapters are thematically interrelated in a systematic descriptive approach, though, each chapter is self-contained and can be read independently from the others. It offers a timely reference of theoretical detonation physics for graduate students as well as professional scientists and engineers.

Shock Wave Science and Technology Reference Library, Vol. 2

Shock Wave Science and Technology Reference Library, Vol. 2 PDF Author: Y. Horie
Publisher: Springer Science & Business Media
ISBN: 3540684085
Category : Science
Languages : en
Pages : 381

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Book Description
This book is the first of several volumes on solids in the Shock Wave Science and Technology Reference Library. This is a unique collection, and the library as a whole sets out to comprehensively and authoritatively cover and review at research level the subject matter with all its ramifications. All the chapters are self-contained and can be read independently of each other, though they are of course thematically interrelated.

Los Alamos Science

Los Alamos Science PDF Author:
Publisher:
ISBN:
Category : Laboratories
Languages : en
Pages : 604

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Book Description