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Full-Text Articles in Explosives Engineering

Dielectric Permittivity Of Pzt 95/5 Ferroelectric Ceramics And 0.27pin-Pmn-0.26pt Single Crystals Under Pulsed High Electric Fields, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Christopher S. Lynch Jan 2024

Dielectric Permittivity Of Pzt 95/5 Ferroelectric Ceramics And 0.27pin-Pmn-0.26pt Single Crystals Under Pulsed High Electric Fields, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Christopher S. Lynch

Mining Engineering Faculty Research & Creative Works

The dependence of the dielectric permittivity of ferroelectric materials on electric field magnitude impacts the performance of ferroelectric devices. In a ferroelectric generator, a shock wave travels through the ferroelectric element and depolarizes it, and surface charges are released from the element electrodes, resulting in the generation of a megawatt power level for several microseconds. The dielectric properties of the compressed and uncompressed zones of the ferroelectric element affect the generated voltage and energy. The results of previous studies indicate that the low-field dielectric permittivity of poled Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 (PZT 95/5) ferroelectrics in the uncompressed zone differs significantly from the high-field …


Effect Of Shock Tunnel Geometry On Shockwave And Vortex Ring Formation, Propagation, And Head On Collision, Rachel L. Bauer, Emily M. Johnson, Alexander D. Douglas, Catherine E. Johnson Aug 2023

Effect Of Shock Tunnel Geometry On Shockwave And Vortex Ring Formation, Propagation, And Head On Collision, Rachel L. Bauer, Emily M. Johnson, Alexander D. Douglas, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Vortex ring research primarily focuses on the formation from circular openings. Consequently, the role of tunnel geometry is less understood, despite there being numerous research studies using noncircular shock tunnels. This experimental study investigated shockwaves and vortex rings from different geometry shock tunnels from formation at the tunnel opening to head on collision with another similarly formed vortex ring using schlieren imaging and statistical analysis. The velocity of the incident shockwave was found to be consistent across all four shock tunnel geometries, which include circle, hexagon, square, and triangle of the same cross-sectional area. The velocity was 1.2 ± 0.007 …


Evaluating Blast Wave Overpressure From Non-Spherical Charges Using Time Of Arrival From High-Speed Video, Kelly Williams, Catherine E. Johnson Jan 2023

Evaluating Blast Wave Overpressure From Non-Spherical Charges Using Time Of Arrival From High-Speed Video, Kelly Williams, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Scaled distance is used to predict blast wave overpressure surrounding the detonation of a known mass of explosive under the assumption that the charge geometry is spherical. Altering charge geometry from spherical overdrives regions of the blast wave resulting in areas of higher overpressures than predicted by scaled distance calculations. Empirical data can be used to scale the blast wave overpressure to cylindrical charges, but available overpressure data for more complex geometries is not available in published literature. In the present study the time of arrival of the blast wave was measured from high-speed video and the Rankine-Hugoniot relationship used …


Analyzing The Effectiveness Of The Gurney Method For Small Scale Fragmentation Propulsion Using Exploding Bridgewire Detonators, Emily M. Johnson, Rachel L. Bauer, Catherine E. Johnson Jan 2023

Analyzing The Effectiveness Of The Gurney Method For Small Scale Fragmentation Propulsion Using Exploding Bridgewire Detonators, Emily M. Johnson, Rachel L. Bauer, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Explosives are common in military, mining, and construction applications where the explosive properties are understood, but mechanics of how the explosive's energy fragments and throws materials are less known. Considering the type of confining material around an explosive, creates variability in fragmentation behavior due to the individual material characteristics. The most common method for assessing fragmentation behavior is the Gurney method, which eliminates any consideration of fragmenting material properties. The Gurney method assumes that, on a large scale, the inconsistencies in material are irrelevant and only the mass of the confiner need be considered. However, it is known in many …


Shock Wave Formation From Head-On Collision Of Two Subsonic Vortex Rings, Rachel L. Bauer, Cody J. Thomas, Everett V.P. Baker, Emily M. Johnson, Kelly R. Williams, Martin J. Langenderfer, Catherine E. Johnson Dec 2022

Shock Wave Formation From Head-On Collision Of Two Subsonic Vortex Rings, Rachel L. Bauer, Cody J. Thomas, Everett V.P. Baker, Emily M. Johnson, Kelly R. Williams, Martin J. Langenderfer, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Vortex ring collisions have attracted intense interest in both water and air studies (Baird in Proc R Soc Lond Ser Math Phys Sci 409:59-65, 1987, Poudel et al. in Phys Fluids 33:096105, 2021, Lim and Nickels in Nature 357:225, 1992, New et al. in Exp Fluids 57:109, 2016, Suzuki et al. in Geophys Res Lett 34, 2007, Yan et al. in J Fluids Eng 140:054502, 2018, New et al. in J Fluid Mech 899, 2020, Cheng et al. in Phys Fluids 31:067107, 2019, Hernández and Reyes in 29:103604, 2017, Mishra et al. in Phys Rev Fluids, 2021, Zednikova et al. …


Low-Intensity Blast Induces Acute Glutamatergic Hyperexcitability In Mouse Hippocampus Leading To Long-Term Learning Deficits And Altered Expression Of Proteins Involved In Synaptic Plasticity And Serine Protease Inhibitors, Shanyan Chen, Heather R. Siedhoff, Hua Zhang, Pei Liu, Ashley Balderrama, Runting Li, Catherine E. Johnson, For Full List Of Authors, See Publisher's Website. Apr 2022

Low-Intensity Blast Induces Acute Glutamatergic Hyperexcitability In Mouse Hippocampus Leading To Long-Term Learning Deficits And Altered Expression Of Proteins Involved In Synaptic Plasticity And Serine Protease Inhibitors, Shanyan Chen, Heather R. Siedhoff, Hua Zhang, Pei Liu, Ashley Balderrama, Runting Li, Catherine E. Johnson, For Full List Of Authors, See Publisher's Website.

Mining Engineering Faculty Research & Creative Works

Neurocognitive consequences of blast-induced traumatic brain injury (bTBI) pose significant concerns for military service members and veterans with the majority of "invisible injury." However, the underlying mechanism of such mild bTBI by low-intensity blast (LIB) exposure for long-term cognitive and mental deficits remains elusive. Our previous studies have shown that mice exposed to LIB result in nanoscale ultrastructural abnormalities in the absence of gross or apparent cellular damage in the brain. Here we tested the hypothesis that glutamatergic hyperexcitability may contribute to long-term learning deficits. Using brain slice electrophysiological recordings, we found an increase in averaged frequencies with a burst …


Investigating Anisotropic Blast Wave Parameters Near The Explosive-Air Boundary Using Computer Simulation And Experimental Techniques With Varying Charge Geometry, Kelly Williams, Catherine E. Johnson Nov 2021

Investigating Anisotropic Blast Wave Parameters Near The Explosive-Air Boundary Using Computer Simulation And Experimental Techniques With Varying Charge Geometry, Kelly Williams, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

The prediction of blast wave overpressure using scaled distance calculations use the charge mass and radial distance variables and assumes that the blast wave is isotropic. Simulations and empirical studies demonstrate that altering the charge geometry results in a significant deviation in overpressure vs orientation. While this effect has been measured for cylinders, truncated cones, and cubes, the mechanisms driving geometric blast wave product anisotropy have not been well defined. Velocity vectors plotted from computer simulations in this study show an isotropic radial flow from the cylindrical charges, while the prismatic charges with rectangle, triangle, and five-point star cross sections …


Additive Manufacturing Of Liners For Shaped Charges, Jason Ho, Cody Lough, Phillip R. Mulligan, Edward C. Kinzel, Catherine E. Johnson Aug 2018

Additive Manufacturing Of Liners For Shaped Charges, Jason Ho, Cody Lough, Phillip R. Mulligan, Edward C. Kinzel, Catherine E. Johnson

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A Shaped Charge (SC) is an explosive device used to focus a detonation in a desired direction, and has applications in oil extraction, weaponry and demolition. The focusing relies on a void in the explosive mass, shaped by a metal liner that becomes a super-heated projectile during detonation. Additive Manufacturing (AM) allows greater design freedom and geometric complexity for the liner portion of the SC. Specifically, hierarchical structuring and functional grading can potentially provide greater velocity, directionality, and efficiency. In this work, Selective Laser Melting (SLM) is used to explore different geometries for an SC liner made out of SS …


Detonation Synthesis Of Alpha-Variant Silicon Carbide, Martin Langenderfer, Catherine E. Johnson, William Fahrenholtz, Vadym Mochalin Jul 2018

Detonation Synthesis Of Alpha-Variant Silicon Carbide, Martin Langenderfer, Catherine E. Johnson, William Fahrenholtz, Vadym Mochalin

Mining Engineering Faculty Research & Creative Works

A recent research study has been undertaken to develop facilities for conducting detonation synthesis of nanomaterials. This process involves a familiar technique that has been utilized for the industrial synthesis of nanodiamonds. Developments through this study have allowed for experimentation with the concept of modifying explosive compositions to induce synthesis of new nanomaterials. Initial experimentation has been conducted with the end goal being synthesis of alpha variant silicon carbide (α-SiC) in the nano-scale. The α-SiC that can be produced through detonation synthesis methods is critical to the ceramics industry because of a number of unique properties of the material. Conventional …


Effect Of Explosive Charge Geometry On Shockwave Propagation, Catherine E. Johnson, Phillip R. Mulligan, Kelly Williams, Martin Langenderfer, Jeffrey Heniff Dec 2017

Effect Of Explosive Charge Geometry On Shockwave Propagation, Catherine E. Johnson, Phillip R. Mulligan, Kelly Williams, Martin Langenderfer, Jeffrey Heniff

Mining Engineering Faculty Research & Creative Works

With advancements in the 3D printing of explosives, the understanding how the shape of an explosive charge influences the energy expansion and subsequently the focusing of energy is becoming increasingly more important. Theoretically, explosive charges could be printed to focus the energy on targets of interest or to synthesize nanomaterials. The first step to quantifying the energy expansion and shock wave convergences for a 3D printed charge is to examine simple geometries of traditional explosive charges (non-3D printed). Detonation of 15 PETN-based primasheet charges in the spherical, cubic, cylindrical, and tetrahedral configurations have been examined in this study. Qualitative data …


Shockwave Interaction With A Cylindrical Structure, Phillip R. Mulligan Dec 2017

Shockwave Interaction With A Cylindrical Structure, Phillip R. Mulligan

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

An increased understanding of the shockwave interaction with a cylindrical structure is the foundation for developing a method to explosively seal a pipe similar to the Deepwater Horizon accident in the Gulf of Mexico. Shockwave interactions with a cylindrical structure have been a reoccurring focus of energetics research. Some of the most notable contributions of non-destructive tests are described in ``The Effects of Nuclear Weapons'' (Glasstone, 1962). The work presented by Glasstone examines shockwave interaction from a 20-megaton bomb with a cylindrical structure. However, the data is limited to a peak overpressure of less than 25 psi, requiring several miles …


Explosively Formed Projectile Soft-Recovery Force Analysis, Laurin Bookout, Phillip R. Mulligan, Jason Baird Dec 2012

Explosively Formed Projectile Soft-Recovery Force Analysis, Laurin Bookout, Phillip R. Mulligan, Jason Baird

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The design of a soft-recovery system is critical to a researcher's ability to analyze hypervelocity projectiles. The researcher may decide to use one method over another based on several criteria, including whether or not non-deformed projectile measurements are required. This report analyzes the forces two different soft-recovery methods impart on the projectiles collected. Method 1 utilized three polyethylene water barrels placed “end-to-end” horizontally, providing 2.6 meters (9 feet) of water to stop the projectile. Method 2 is a modification of the soft-recovery method utilized in “Soft-Recovery of Explosively Formed Penetrators” by Lambert and Pope. This method utilizes a series of …


Note: Utilizing Pb(Zr 0.95ti 0.05)O₃ Ferroelectric Ceramics To Scale Down Autonomous Explosive-Driven Shock-Wave Ferroelectric Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev Jul 2012

Note: Utilizing Pb(Zr 0.95ti 0.05)O₃ Ferroelectric Ceramics To Scale Down Autonomous Explosive-Driven Shock-Wave Ferroelectric Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev

Mining Engineering Faculty Research & Creative Works

Further miniaturization of recently designed autonomous ferroelectric generators (FEGs) S. I. Shkuratov, J. Baird, and E. F. Talantsev, Rev. Sci. Instrum. 82, 086107 (2011), which are based on the effect of explosive-shock-wave depolarization of poled ferroelectrics is achieved. The key miniaturization factor was the utilization of high-energy density Pb(Zr0.95Ti0.05)O3 (PZT 955) ferroelectric ceramics as energy-carrying elements of FEGs instead of the previously used Pb(Zr0.52Ti0.48)O3 (PZT 5248). A series of experiments demonstrated that FEGs based on smaller PZT 955 ferroelectric elements are capable of producing the same output voltage as those …


The Effects Of The Flyer Plate's Radius Of Curvature On The Performance Of An Explosively Formed Projectile, Phillip R. Mulligan, Jason Baird, Joshua Hoffman Jul 2012

The Effects Of The Flyer Plate's Radius Of Curvature On The Performance Of An Explosively Formed Projectile, Phillip R. Mulligan, Jason Baird, Joshua Hoffman

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

An explosively formed projectile (EFP) is known for its ability to penetrate vehicle armor effectively. Understanding how an EFP’s physical parameters affect its performance is crucial to development of armor capable of defeating such devices. The present study uses two flyer plate radii of curvature to identify the experimental effects of the flyer plate’s radius of curvature on the measured projectile velocity, depth of penetration, and projectile shape. The Gurney equation is an algebraic relationship for estimating the velocity imparted to a metal plate in contact with detonating explosives. The authors of this research used a form of the Gurney …


Electric Field-Free Gas Breakdown In Explosively Driven Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev, Larry L. Altgilbers Jul 2010

Electric Field-Free Gas Breakdown In Explosively Driven Generators, S. I. Shkuratov, Jason Baird, E. F. Talantsev, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

All known types of gas discharges require an electric field to initiate them. We are reporting on a unique type of gas breakdown in explosively driven generators that does not require an electric field.


Explosive-Driven Mini-System Based On Shock Wave Ferromagnetic Seed Source And Loop Magnetic Flux Compression Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers Jun 2007

Explosive-Driven Mini-System Based On Shock Wave Ferromagnetic Seed Source And Loop Magnetic Flux Compression Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

Completely explosive pulsed power mini-systems based on the transverse shock wave ferromagnetic generator (FMG) served as a seed source and loop magnetic flux compression generator (LFCG) as a pulsed power amplifier were proposed, designed, built and tested. The physical principles and design of the developed FMG-LFCG system are described in detail. Experimental data are presented for the explosive operation and electrical performance of the system.


New Concept For Constructing An Autonomous Completely Explosive Pulsed Power System: Transverse Shock Wave Ferromagnetic Primary Power Source And Loop Flux Compression Amplifier, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers Nov 2006

New Concept For Constructing An Autonomous Completely Explosive Pulsed Power System: Transverse Shock Wave Ferromagnetic Primary Power Source And Loop Flux Compression Amplifier, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

A new design idea for a compact, autonomous, completely explosive pulsed power system is proposed. The system is based on the shock wave ferromagnetic generator (FMG) as a primary power source and a loop magnetic flux compression generator (LFCG) as a pulsed power amplifier. The FMG primary power source utilizes the effect of transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets to produce the seed current. Results are presented of an experimental study and digital simulation of operation of the FMG-LFCG system


Using Coupled Eulerian And Lagrangian Grids To Model Explosive Interactions With Buildings, Braden Lusk, William P. Schonberg, Jason Baird, Robert S. Woodley, Warren Noll Nov 2006

Using Coupled Eulerian And Lagrangian Grids To Model Explosive Interactions With Buildings, Braden Lusk, William P. Schonberg, Jason Baird, Robert S. Woodley, Warren Noll

Mining Engineering Faculty Research & Creative Works

This paper presents the development of a computational model that can be used to study the interactions between structures and detonating explosives contained within them. This model was developed as part of an effort to develop a rubble characterization model for use in AmmoSIM, an agent based urban tactical decision aid (UTDA) software for weapon-target pairing. The rubble pile created following the collapse of a building in a combat situation can significantly impact mission accomplishment, particularly in the area of movement and maneuver. The information provided by AmmoSIM will enable both platoon level and command center staff to make informed …


Compact Autonomous Explosive-Driven Pulsed Power System Based On A Capacitive Energy Storage Charged By A High-Voltage Shock-Wave Ferromagnetic Generator, S. I. Shkuratov, E. F. Talantsev, Jason Baird, Larry L. Altgilbers, A. H. Stults Jun 2006

Compact Autonomous Explosive-Driven Pulsed Power System Based On A Capacitive Energy Storage Charged By A High-Voltage Shock-Wave Ferromagnetic Generator, S. I. Shkuratov, E. F. Talantsev, Jason Baird, Larry L. Altgilbers, A. H. Stults

Mining Engineering Faculty Research & Creative Works

A new concept for constructing compact autonomous pulsed power systems is presented. This concept utilizes a high-voltage explosive-driven shock-wave ferromagnetic generator (FMG) as a charging source for capacitive energy storage. It has been experimentally demonstrated that miniature FMGs (22-25 cm³ in size and 84-95 g in mass) developed for these experiments can be successfully used to charge capacitor banks. The FMGs, containing Nd₂Fe₁₄B energy-carrying elements, provided pulsed powers of 35-45 kW in times ranging from 10 to 15 µs. A methodology was developed for digital simulation of the operation of the transverse FMG. Experimental results that were obtained are in …


Longitudinal Shock Wave Depolarization Of Pb(Zr₅₂Ti₄₈)O₃ Polycrystalline Ferroelectrics And Their Utilization In Explosive Pulsed Power, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Henryk Temkin, Larry L. Altgilbers, Allen H. Stults Jan 2006

Longitudinal Shock Wave Depolarization Of Pb(Zr₅₂Ti₄₈)O₃ Polycrystalline Ferroelectrics And Their Utilization In Explosive Pulsed Power, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Henryk Temkin, Larry L. Altgilbers, Allen H. Stults

Mining Engineering Faculty Research & Creative Works

A poled lead zirconate titanate Pb(Zr52Ti48)O3 (PZT) polycrystalline piezoelectric ceramic energy-carrying element of a compact explosive-driven power generator was subjected to a longitudinal explosive shock wave (the wave front traveled along the polarization vector P0). The shock compression of the element at pressures of 1.5-3.8 GPa caused almost complete depolarization of the sample. Shock wave velocity in the PZT was determined to be 3.94 ± 0.27 km/s. The electric charge stored in a ferroelectric, due to its remnant polarization, is released during a short time interval and can be transformed into pulsed power. Compact explosive-driven power sources utilizing longitudinal shock …


Completely Explosive Autonomous High-Voltage Pulsed-Power System Based On Shockwave Ferromagnetic Primary Power Source And Spiral Vector Inversion Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Millard F. Rose, Zachary Shotts, Z. Roberts, Allen H. Stults, Larry L. Altgilbers Jan 2006

Completely Explosive Autonomous High-Voltage Pulsed-Power System Based On Shockwave Ferromagnetic Primary Power Source And Spiral Vector Inversion Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Millard F. Rose, Zachary Shotts, Z. Roberts, Allen H. Stults, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

Novel explosive and conventional pulsed-power technologies were combined, and a series of explosive-driven high-voltage power supplies was designed, built, and tested. The power supply contained an explosive-driven high-voltage primary power source based on the fundamental physical effect of shockwave demagnetization of Nd2 Fe14B high-energy ferromagnet and a power-conditioning stage. The volume of the energy-carrying ferromagnetic elements in the shockwave ferromagnetic generators (FMGs) was 8.75 cm3. The power-conditioning stage was based on the spiral vector inversion generator (VIG). The combined FMG-VIG system demonstrated successful operation and good performance. The output-voltage pulse amplitude of the combined FMG-VIG …


Completely Explosive Ultracompact High-Voltage Nanosecond Pulse-Generating System, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Millard F. Rose, Zachary Shotts, Larry L. Altgilbers, Allen H. Stults Jan 2006

Completely Explosive Ultracompact High-Voltage Nanosecond Pulse-Generating System, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Millard F. Rose, Zachary Shotts, Larry L. Altgilbers, Allen H. Stults

Mining Engineering Faculty Research & Creative Works

A conventional pulsed power technology has been combined with an explosive pulsed power technology to produce an autonomous high-voltage power supply. The power supply contained an explosive-driven high-voltage primary power source and a power-conditioning stage. The ultracompact explosive-driven primary power source was based on the physical effect of shock-wave depolarization of high-energy Pb(Zr52Ti48)O3 ferroelectric material. The volume of the energy-carrying ferroelectric elements in the shock-wave ferroelectric generators (SWFEGs) varied from 1.2 to 2.6 cm3. The power-conditioning stage was based on the spiral vector inversion generator (VIG). The SWFEG-VIG system demonstrated successful operation and good performance. The amplitude of the output …


Pulse Charging Of Capacitor Bank By Explosive-Driven Shock Wave Ferroelectric Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers Jan 2006

Pulse Charging Of Capacitor Bank By Explosive-Driven Shock Wave Ferroelectric Generator, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

Ultracompact explosive-driven shock wave ferroelectric generators (FEGs) were used as autonomous primary power sources for charging capacitor banks of different capacitance. The FEGs utilized longitudinal (when the shock wave propagates along the polarization vector P) shock wave depolarization of Pb(Zr52Ti48)O3 (PZT) polycrystalline ferroelectric ceramic. PZT disks having diameters ranging from 25 to 27 mm and three different thicknesses: 0.65, 2.1, and 5.1 mm. It was experimentally shown that during the charging process the FEGs were capable of producing pulsed power with peak amplitudes up to 0.3 MW. Results for charging voltage, electric charge transfer and …


Transverse Explosive Shock-Wave Compression Of Nd₂Fe₁₄B High-Energy Hard Ferromagnets: Induced Magnetic Phase Transition, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Larry L. Altgilbers, Allen H. Stults Jan 2006

Transverse Explosive Shock-Wave Compression Of Nd₂Fe₁₄B High-Energy Hard Ferromagnets: Induced Magnetic Phase Transition, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Larry L. Altgilbers, Allen H. Stults

Mining Engineering Faculty Research & Creative Works

Investigations of the magnetic phase state of Nd2Fe14B high-energy hard ferromagnets under the action of an explosive shock wave traveling across the magnetization vector, M, have been performed. We demonstrate that the transverse shock-wave compression of an Nd2Fe14B hard ferromagnet with pressure at the shock wave front of P = 22.3 GPa causes a hard ferromagnet — to — weak magnet phase transition. Due to this phase transition, the magnetostatic energy stored for an indefinite period of time in the Nd2Fe14B ferromagnet is released within a short time interval and can be transformed into pulsed primary power. Based on this …


Compact Autonomous Completely Explosive Pulsed Power System Based On Transverse Shock Wave Demagnetization Of Nd₂Fe₁₄B And Magnetic Flux Compression, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers Nov 2005

Compact Autonomous Completely Explosive Pulsed Power System Based On Transverse Shock Wave Demagnetization Of Nd₂Fe₁₄B And Magnetic Flux Compression, Sergey I. Shkuratov, Evgueni F. Talantsev, Jason Baird, Allen H. Stults, Larry L. Altgilbers

Mining Engineering Faculty Research & Creative Works

The design and performance of a compact autonomous completely explosive pulsed power system based on two physical effects, the transverse shock wave demagnetization of Nd2Fe14B high-energy hard ferromagnets and magnetic flux compression, are presented. A transverse shock wave ferromagnetic generator (FMG) served as a seed source, and a compact helical magnetic flux compression generator (FCG) was used as a pulsed power amplifier. Results of a theoretical and experimental study demonstrated reliable operation of the proposed FMG-FCG system. The methodology for analytical calculation of seed current amplitude is developed.


Pulsed Charging Of Capacitor Bank By Compact Explosive-Driven High-Voltage Primary Power Source Based On Longitudinal Shock Wave Depolarization Of Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Evgueni F. Talantsev, Yaroslav Tkach, Larry L. Altgilbers, Allen H. Stults, Stanislav V. Kolossenok Jan 2005

Pulsed Charging Of Capacitor Bank By Compact Explosive-Driven High-Voltage Primary Power Source Based On Longitudinal Shock Wave Depolarization Of Ferroelectric Ceramics, Sergey I. Shkuratov, Jason Baird, Evgueni F. Talantsev, Yaroslav Tkach, Larry L. Altgilbers, Allen H. Stults, Stanislav V. Kolossenok

Mining Engineering Faculty Research & Creative Works

Results of the investigation of the operation of autonomous ultracompact explosive-driven high-voltage primary power sources based on longitudinal (when the shock wave propagates along the polarization vector P0) shock wave depolarization of ferroelectric materials in the open circuit and charging modes are presented. The energy-carrying elements of shock wave ferroelectric generators (FEGs) were poled lead zirconate titanate (PZT) Pb(Zr52Ti48)O3 polycrystalline piezoelectric ceramic disks with volume 0.35 cm3. The PZT modules were shock compressed in the stress range from 1.5 to 3.8 GPa by a longitudinal shock wave generated by high explosives. In the charging mode, the FEGs provided pulsed power …


The Causes Of Armature Surface Fracturing Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey Jan 2002

The Causes Of Armature Surface Fracturing Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

Aluminum and copper tubes filled with explosive were tested during this study of high strain rate effects, as an adjunct to helical flux-compression generator research at the University of Missouri-Rolla, directly affecting the understanding of flux cutoff and high strain-rate changes in generator armatures. Longitudinal cracks characteristically developed in the outer surface of armatures at a smaller expansion ratio than predicted. These cracks occurred within two diameters of the detonator end of the armature but did not extend when the tubing expanded under explosive pressurization. Such cracks appear to cause magnetic flux cutoff, and flux losses seriously affect energy conversion …


Design Of A Hypersonic Waterjet Apparatus Driven By High Explosives, B. L. Weeks, J. Klosterman, Paul Nicholas Worsey Aug 2001

Design Of A Hypersonic Waterjet Apparatus Driven By High Explosives, B. L. Weeks, J. Klosterman, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

The design and construction of a hypersonic waterjet apparatus is described. Jet velocities from 0.5 to 5 km/s have been achieved using a high explosive charge. Images are obtained in situ on various target substrates using a high-speed framing camera. Experimental results are shown for the impact of high velocity waterjets on propellants and high explosive samples. By observing the impact of the waterjet at a wide range of velocities a safety threshold can be determined where no reaction takes place.


Effects Of Defects On Armatures Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey, Mark F. C. Schmidt Jan 2001

Effects Of Defects On Armatures Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey, Mark F. C. Schmidt

Mining Engineering Faculty Research & Creative Works

Tubes of aluminum and copper filled with C-4 high-explosive were tested during this study of the effects of explosive flaws and voids, their sizes and locations, and of the effects of armature machining tolerances on the expansion characteristics of armatures within helical flux-compression generators. Flaws and voids were introduced into the explosive fill of 6061-T6 aluminum armatures during assembly. The defects were located along the major axis of the fill, midway between the major axis and the explosive/armature interface, and at the interface. The resulting effects on armature expansion were recorded by high-speed framing camera, intensified charge-coupled display (ICCD) photography …


Surface Fracturing Of Armatures Within Helical Flux-Compression Generators, Paul Nicholas Worsey, Jason Baird Jan 2001

Surface Fracturing Of Armatures Within Helical Flux-Compression Generators, Paul Nicholas Worsey, Jason Baird

Mining Engineering Faculty Research & Creative Works

Tubes of aluminum and of copper filled with C-4 high-explosive were tested during this study of high strain rate effects within thin metallic structures performed as an adjunct to helical flux-compression generator research at the University of Missouri-Rolla. Focusing on the stresses within a relatively thin metallic structure when brisant explosives abutting the structure are detonated, this study directly affects the understanding of flux cutoff and high strain-rate resistivity changes in an expanding armature. The detonation wave is compressive, and the shock waves resulting from its transmission into a thin metallic structure cause both compressive and tensile regions, posing an …