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Full-Text Articles in Engineering

Hybrid Mechanism Of Electrical Breakdown In Ferroelectric Materials Under High-Pressure Shock Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase, Christopher S. Lynch Jul 2024

Hybrid Mechanism Of Electrical Breakdown In Ferroelectric Materials Under High-Pressure Shock Loading, Sergey I. Shkuratov, Jason Baird, Vladimir G. Antipov, Jay B. Chase, Christopher S. Lynch

Mining Engineering Faculty Research & Creative Works

The unique ability of ferroelectrics to generate high voltage under shock loading is limited by electrical breakdown within the shock-compressed ferroelectric material. Breakdown is a hybrid process of initiation and growth. The possible mechanisms of electrical breakdown in ferroelectric films and bulk ceramics subjected to high-pressure shock loading are discussed and experiments designed to elucidate which mechanisms govern breakdown. Gigapascal shock loading experiments were performed on poled Pb0.99(Zr0.95Ti0.05)0.98Nb0.02O3 ferroelectric film specimens in the range of 32-156 μm thickness to determine the dependence of the breakdown field on thickness and …


The Interplay Of Casing Material And Detonation Wave Shock Parameters In Steel Witness Plate Dent Formation, Emily M. Johnson, Catherine E. Johnson May 2024

The Interplay Of Casing Material And Detonation Wave Shock Parameters In Steel Witness Plate Dent Formation, Emily M. Johnson, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

This Study Uses Both Experimentation and Simulation to Investigate How Varying Casing Material Around Cylindrical Composition-B Charges Affects Witness Plate Response and Diagnoses the Cause of the Differences in the Dents Produced. through Experimentation, It Was Found that Consistent Dents Are Produced from Repeated Tests and Characteristically Different Dents Are Produced by Charges with Different Casing Material. Charges Cased in Viscoelastic Materials Produced Shallower Dents Than Those Without Casing. Simulation Was Validated Against the Experimental Dents, and the Detonation Wave Parameters Were Measured for 25 Differently Cased Charges: 15 Metals and 10 Polymers. Regression Fit Relationships Were Derived Relating Dent …


Tnt Equivalence Of Binary Energetics, Gracie Mae James Apr 2024

Tnt Equivalence Of Binary Energetics, Gracie Mae James

Undergraduate Research Conference at Missouri S&T

TNT equivalency is a standard used to measure and quantify the effects of energetic materials. Using these equivalencies, the safety factors for minimum distances and storage of explosives are determined. Having a known TNT equivalence of energetic materials also helps estimate potential blast damage and risks for individuals. The TNT equivalencies for numerous energetic materials, such as binaries, have no published values, but are regularly used in industry, military, and research testing. To determine TNT equivalence, three tests will be performed: 1) a plate dent test, 2) air blast tests to measure air overpressure and calculate impulse, and 3) velocity …


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 …


High Strain Rate Analysis Of 3d Printed Concrete As Compared To Conventionally Cast Concrete, Weston Mcleod Thomsen Jan 2024

High Strain Rate Analysis Of 3d Printed Concrete As Compared To Conventionally Cast Concrete, Weston Mcleod Thomsen

Masters Theses

"3D Printed Concrete (3DPC) is a developing method of construction that has advantages over conventional methods, including formwork reduction, complex geometry, and expedited construction. This technology has potential benefits for the military when considering the austere environments that forward operating bases are built in. This study aims to assess 3DPC applications in protective structures that protect critical assets from explosive blasts. These protective structures experience a high-strain rate response during blast loading of the structure, and the effects of this have yet to be analyzed in the literature concerning 3DPC. With the lack of prior research, the focus here will …


Quantitative Proteomic Profiling In Brain Subregions Of Mice Exposed To Open-Field Low-Intensity Blast Reveals Position-Dependent Blast Effects, M. Jackson, S. Chen, P. Liu, M. Langenderfer, C. Li, H. R. Siedhoff, A. Balderrama, R. Li, Catherine E. Johnson, C. M. Greenlief, I. Cernak, R. G. Depalma, J. Cui Jan 2024

Quantitative Proteomic Profiling In Brain Subregions Of Mice Exposed To Open-Field Low-Intensity Blast Reveals Position-Dependent Blast Effects, M. Jackson, S. Chen, P. Liu, M. Langenderfer, C. Li, H. R. Siedhoff, A. Balderrama, R. Li, Catherine E. Johnson, C. M. Greenlief, I. Cernak, R. G. Depalma, J. Cui

Mining Engineering Faculty Research & Creative Works

The Neurological Consequences of Combat Blast-Induced Neurotrauma (BINT) Pose Important Clinical Concerns for Military Service Members and Veterans. Previous Studies Have Shown that Low-Intensity Blast (LIB) Results in BINT with Multifaceted Characteristics in Mice Exposed to Open-Field Blast in Prone Position. Although the Prone Position is Natural for Rodents, Experimental Models of Blast using This Position Do Not Represent Common Scenarios of Human Standing While Being Exposed to Blast during Deployment or Military Training. in This Study, We Used Our Previously Developed BINT Mouse Model of Open-Field LIB with Mice in an Upright Position and Then Used Quantitative Proteomics and …


A Review Of Current Safe Distance Calculations And The Risk Of Mild Traumatic Brain Injury, A. R. Loflin, C. E. Johnson Jan 2024

A Review Of Current Safe Distance Calculations And The Risk Of Mild Traumatic Brain Injury, A. R. Loflin, C. E. Johnson

Mining Engineering Faculty Research & Creative Works

Explosive breaching is a tactic operational professionals use to gain rapid entry and tactical advantage. This tactic exposes individuals to repeated low-level blasts (LLB), overpressure exposure generally occurring from user-directed munitions. The experimentation described in this paper highlights the need for further research into implementing explosives in tactical situations, specifically in confined areas, and the effects on individuals exposed. While current safety calculations predict peak pressures from an open-air detonation, this study incorporates the impulse of the total explosive event in a confined space. Sixteen explosive events were conducted to measure peak overpressures of the total duration of the event …


Investigation Into Helmet–Head Shock Wave Interactions At Low Overpressures Through Free-Field Blasts And Schlieren Imagery, C. J.H. Thomas, Catherine E. Johnson Jan 2024

Investigation Into Helmet–Head Shock Wave Interactions At Low Overpressures Through Free-Field Blasts And Schlieren Imagery, C. J.H. Thomas, Catherine E. Johnson

Mining Engineering Faculty Research & Creative Works

Brain Injuries in Warfighters Due to Low-Level Blasts, Even While Wearing a Helmet, Are Common. Understanding How the Form of a Shock Wave Changes When Impacting a Head Donning a Helmet May Present Solutions to Reducing Shock Loading on the Head, Thereby Reducing the Prevalence of Blast-Induced Traumatic Brain Injury. a Manikin with PCB Piezoelectric Transducers throughout the Head Was Exposed to Low-Pressure Free-Field Blasts using an RDX-Based Explosive Charge Designed to Output a Side-On overpressure of 4 Pounds Per Square Inch (Psi) [27.5 Kilopascals (KPa)] with and Without a Helmet. Orientations of 0, 45, 90, 135, and 180 Degrees …


Investigating Detonation Parameters Through The Plate Dent Test: A Novel Approach For Characterizing Detonation Curvature And Thickness, Emily Michelle Johnson Jan 2024

Investigating Detonation Parameters Through The Plate Dent Test: A Novel Approach For Characterizing Detonation Curvature And Thickness, Emily Michelle Johnson

Doctoral Dissertations

Detonation is the driving factor behind how an explosive, used in an array of applications, performs. Understanding and measuring detonation parameters of an explosive is key in explosive charge design and application. Currently, determining parameters is costly as the instrumentation needed is expensive in terms of price, maintenance, and personnel. This research examines two methods of determining detonation parameters through measurement of secondary material response to the detonation wave in an effort to provide an alternate, simple, and inexpensive method of measurement. The first of these studies focuses on the Gurney Model and demonstrates that the model's accuracy was diminished …