Download or read book Shock Initiation of PBX 9502 at Elevated Temperatures written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Increased Shock Sensitivity of PBX 9502 at High Temperature written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Temperature dependent Shock Initiation of TATB based High Explosives written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of temperature on the shock sensitivity of two TATB formulations PBX 9502 and LX-17 are studied over the temperature range -54°C to 252°C. The shock Hugoniot curves over this same temperature range are developed. Thermal expansion properties and porosities are used to help determine the mechanisms of thermal sensitization. Impact sensitivities over the range from ambient to 300°C are reported. Analyses of these results imply that thermal sensitization is the result of purely chemical kinetics enhancement and intracrystalline hot-spot growth. Additional results on the ambient shock sensitivity of PBX 9502 and LX-17 following thermal cycling to 252°C and back to ambient is presented.

Download or read book Shock Initiation Experiments on Ratchet Grown PBX 9502 written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This study compares the shock initiation behavior of PBX 9502 pressed to less than nominal density (nominal density is 1.890 ± 0.005 g/cm3) with PBX 9502 pressed to nominal density and then ''ratchet grown'' to low density. PBX 9502 is an insensitive plastic bonded explosive consisting of 95 weight % dry-aminated tri-amino-tri-nitro-benzene (TATB) and 5 weight % Kel-F 800 plastic binder. ''Ratchet growth'' - an irreversible increase in specific volume - occurs when an explosive based on TATB is temperature cycled. The design of our study is as follows: PBX 9502, all from the same lot, received the following four treatments. Samples in the first group were pressed to less than nominal density. These were not ratchet grown and used as a baseline. Samples in the second group were pressed to nominal density and then ratchet grown by temperature cycling 30 times between -54 C and +80 C. Samples in the final group were pressed to nominal density and cut into 100 mm by 25.4 mm diameter cylinders. During thermal cycling the cylinders were axially constrained by a 100 psi load. Samples for shock initiation experiments were cut perpendicular (disks) and parallel (slabs) to the axial load. The four sample groups can be summarized with the terms pressed low, ratchet grown/no load, axial load/disks, and axial load/slabs. All samples were shock initiated with nearly identical inputs in plate impact experiments carried out on a gas gun. Wave profiles were measured after propagation through 3, 4, 5, and 6 mm of explosive. Side by side comparison of wave profiles from different samples is used as a measure of relative sensitivity. All reduced density samples were more shock sensitive than nominal density PBX 9502. Differences in shock sensitivity between ratchet grown and pressed to low density PBX 9502 were small, but the low density pressings are slightly more sensitive than the ratchet grown samples.

Download or read book Shock Compression of Condensed Matter 1995 written by S. C. Schmidt and published by Springer. This book was released on 1996 with total page 688 pages. Available in PDF, EPUB and Kindle. Book excerpt: Proceedings of the Conference of the American Physical Society Topical Group on shock compression of condensed matter.

Download or read book Shock Initiation of PBX 9502 EDC 35 and LX 17 written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Detonation Shock Dynamics Calibration for PBX 9502 with Temperature Density and Material Lot Variations written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a methodology for scaling the detonation shock dynamics D{sub n}[[kappa]] calibration function to accommodate variations in the HE starting material. We apply our model to the insensitive TATB-based explosive PBX 9502, for which we have enough front curvature rate stick data to characterize three material attributes: initial temperature T0, nominal density [rho]0, and manufacturing lot (representing different microstructures). A useful feature of the model is that it returns an absolute estimate for the reaction zone thickness, [delta]. Lacking demonstrated material metrics(s), we express microstructural variation indirectly, in terms of its effect on [delta]. This results in a D{sub n}[[kappa]] function that depends on T0, [rho]0, and [delta]. After examining the separate effects of each parameter on D{sub n}[[kappa]], we compute an arc geometry as a validation problem. We compare the calculation to a PBX 9502 arc experiment that was pressed from one of the calibrated HE lots. The agreement between the model and experiment is excellent. We compute worst, nominal, and best-performing material parameter combinations to show how much difference accrues throughout the arc.

Download or read book Ignition and Growth Modeling of the Shock Initiation of PBX 9502 at 55C and 196C written by and published by . This book was released on 2015 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Thermal Response of TATB Based PBXs written by and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the design mode of operation, TATB-based PBXs, such as PBX 9502 or LX-17, are promptly initiated by a detonator and booster system. In abnormal situations, such as accidents, a wide variety of non-design-mode insults can arise and it is desirable that these do not produce detonation but rather that, at most, they lead to a low chemical energy release. The most significant abnormal hazard is the direct shock initiation threat arising from high-velocity fragment impact. This is quite well defined and may result in a detonative response if the fragment is large enough and fast enough. However, it is of considerably greater significance to the safety envelope of these explosives whether they are at all capable of DDT (deflagration-to-detonation transition), either at ambient or elevated temperatures since accidental insults to the explosive, either mechanical or thermal, that may produce local burning are both more numerous and more likely than shock loading. The purpose of this document is to demonstrate, based on the accumulated body of conservative experimental testing, that in explosive geometries and masses relevant to the Weapons Program, TATB-based PBXs do not present a deflagration-to-detonation transition (DDT) hazard at any temperature. This is a significant statement since it removes detonative outcome concerns from the majority of insult scenarios on TATB-based charges. It does not address the response of included detonator and booster assemblies, the response of which must be considered separately.

Download or read book Shock Initiation of Damaged Explosives written by and published by . This book was released on 2009 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Explosive and propellant charges are subjected to various mechanical and thermal insults that can increase their sensitivity over the course of their lifetimes. To quantify this effect, shock initiation experiments were performed on mechanically and thermally damaged LX-04 (85% HMX, 15% Viton by weight) and PBX 9502 (95% TATB, 5% Kel-F by weight) to obtain in-situ manganin pressure gauge data and run distances to detonation at various shock pressures. We report the behavior of the HMX-based explosive LX-04 that was damaged mechanically by applying a compressive load of 600 psi for 20,000 cycles, thus creating many small narrow cracks, or by cutting wedge shaped parts that were then loosely reassembled, thus creating a few large cracks. The thermally damaged LX-04 charges were heated to 190 C for long enough for the beta to delta solid - solid phase transition to occur, and then cooled to ambient temperature. Mechanically damaged LX-04 exhibited only slightly increased shock sensitivity, while thermally damaged LX-04 was much more shock sensitive. Similarly, the insensitive explosive PBX 9502 was mechanically damaged using the same two techniques. Since PBX 9502 does not undergo a solid - solid phase transition but does undergo irreversible or 'rachet' growth when thermally cycled, thermal damage to PBX 9502 was induced by this procedure. As for LX-04, the thermally damaged PBX 9502 demonstrated a greater shock sensitivity than mechanically damaged PBX 9502. The Ignition and Growth reactive flow model calculated the increased sensitivities by igniting more damaged LX-04 and PBX 9502 near the shock front based on the measured densities (porosities) of the damaged charges.

Download or read book Numerical Modeling of Explosives and Propellants written by Charles L. Mader and published by CRC Press. This book was released on 2007-10-18 with total page 539 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Numerical Modeling of Explosives and Propellants Second Edition written by Charles L. Mader and published by CRC Press. This book was released on 1997-08-29 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Front Curvature Rate Stick Measurements and Detonation Shock Dynamics Calibration for PBX 9502 Over a Wide Temperature Range written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Detonation velocity and wave shape are measured for PBX 9502 (95 wt.% TATB, 5 wt.% Kel-F 800) rate sticks at the temperatures [minus]55, 25, and 75 C. At each temperature three different diameters were fired: 50 mm, 18 mm, and 8, 10, and 12 mm respectively for the hot, ambient, and cold sticks. The measured wave shapes are fit with an analytic form and the fitting parameters are tabulated along with thermal expansion and diameter effect data. The simplest detonation shock dynamics (DSD) model assumes a unique calibration function relating the local normal wave speed D[sub n] to the local total curvature [kappa]. The data confirm this notion for sufficiently small curvature, but at large curvature the curves for different charge diameters diverge. Global optimization is used to determine a best single D[sub n]-[kappa] function at each initial temperature T[sub 0]. From these curves a D[sub n]([kappa], T[sub 0]) calibration surface is generated that allows computation of problems with temperature gradients.

Download or read book Shock Waves in Condensed Matter 1983 written by J.R. Asay and published by Elsevier. This book was released on 2012-12-02 with total page 673 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock Waves in Condensed Matter – 1983 covers the proceedings of the American Physical Society Topical Conference, held in Santa Fe, New Mexico on July 18-21, 1983. The book focuses on the response of matter to dynamic high pressure and temperature. The selection first elaborates on the review of theoretical calculations of phase transitions and comparisons with experimental results; theoretical and experimental studies of shock-compressed benzene and polybutene; and theory of the iron equation of state and melting curve to very high pressures. The text then ponders on nonhydrostatic effects in stress-wave induced phase transformation of calcite; Bauschinger effect model suitable for use in large computer codes; and strain rate sensitivity prediction for porous bed compaction. The manuscript takes a look at flaw nucleation and energetics of dynamic fragmentation, shock loading behavior of fused quartz, and aluminum damage simulation in high-velocity impact. Shock wave diagnostics by time-resolved infrared radiometry and non-linear Raman spectroscopy; Raman scattering temperature measurement behind a shock wave; and experiments and simulation on laser-driven shock wave evolution in aluminum targets are also discussed. The selection is a dependable reference for scientists and readers interested in the response of matter when exposed to dynamic high pressure and temperature.

Download or read book Shock Sensitivity of IHE at Elevated Temperatures written by and published by . This book was released on 1993 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Insensitive high explosives (IHE's) based on triamino-trinitrobenzene (TATB) have been demonstrated to be very insensitive to shock, thermal, friction and other stimuli. Hazard scenarios can involve more than one stimulus, such as heating followed by fragment impact (shock). The shock sensitivity of the IHE's LX-17 and PBX-9502 preheated to a temperature (250°C) just below thermal runaway is quantitatively studied using embedded manganin pressure gauges. The thermal expansion of TATB to 250°C is measured to determine the state of the explosive prior to shock initiation. LX-17 and PBX-9502 are found to be significantly more sensitive at 250°C than at lower temperatures, but still less sensitive than ambient temperature HMX-based explosives. An ignition and growth reactive flow computer model of the shock initiation of hot IHE is developed to allow predictions of the response of hot IHE to impact scenarios which can not be tested directly.

Download or read book High temperature Shock Initiation of Explosives written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Initiation of Preshocked High Explosives PBX 9404 PBX 9502 PBX 9501 Monitored with In material Magnetic Gauging written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Desensitization of explosives by preshocking is being studied using the well-supported plane shock waves generated by a gas gun. Evolution of the waves in the explosive is monitored using in-material multiple magnetic gauges to measure particle velocity in the lagrangian frame, over ≈ 3[mu]s of run. PBX-9404, PBX-9502 have been studied, at pressures up to 10.5 GPa. A substantial extension of the run to detonation is observed in PBX-9404, with the run beginning approximately at the end of the preshocked region. A reactive wave is observed while the preshock persists in both PBX-9404 and PBX-9501, but evidently does not contribute to the detonation wave or shorten the run to detonation. PBX-9502 is inert at pressures accessible with the gas gun, but serves to clarify the progress of multiple shocks over the off-Hugoniot EOS surface and the shock dynamics of wave coalescence.