John P. Borg
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Uncertainty analysis for transverse surface velocity measurements Open
Transverse surface velocity measurements are fundamental to performing pressure-shear plate impact experiments. Recent works have utilized slight variations of traditional velocimetry techniques that measure apparent velocity from a combin…
Uniaxial wave propagation through copper mountain sandstone Open
Copper Mountain sandstone samples of thicknesses varying from 1.0mm to 3.6mm were tested in plane strain configuration at impact velocities from 168m/s to 529m/s. Two-dimensional (2D) images of sandstone samples, etched in a 1% Buffered Ox…
A direct comparison of transverse velocimetry techniques using photon Doppler velocimetry (PDV) in oblique impact experiments Open
Photon Doppler velocimetry has been used increasingly to measure transverse velocity in dynamic experiments. This work presents results of an oblique impact experiment which was performed using a slotted-barrel gas gun to generate normal a…
Shape charge automated design: Applying DAKOTA to kinetic energy optimization Open
Advances in computational power present an opportunity to further optimize the design of an engineered energetic system. This work presents the application of a proposed optimization scheme which combines the shock-physics hydrocode CTH wi…
Shock Processes in Water: Multi-Scale Comparison and Experimental Results Open
Water as the most common fluid on earth has extraordinary properties. The understanding of the dynamic response of water is important to planetary physics, biology and medicine. Inspired by the relationship between shockwave thicknesses an…
Dynamic response of graphene and yttria-stabilized zirconia (YSZ) composites Open
A series of dynamic compaction studies were performed on yttria-stabilized zirconia (YSZ) and graphene composites using uniaxial flyer plate impact experiments. Studies aimed to characterize variation in dynamic behavior with respect to mo…
High Strain-rate Shear and Friction Characterization of Fully-Dense Polyurethane and Epoxy Open
The characterization of polymer behavior at high strain-rates is a critical area of research driven by the use of polymers as adhesives, structural components, or as binders for energetic systems. Previous investigations have successfully …
Mesoscale simulations of shock compaction of a granular ceramic: effects of mesostructure and mixed-cell strength treatment Open
The shock response of granular materials is important in a variety of contexts but the precise dynamics of grains during compaction is poorly understood. Here we use 2D mesoscale numerical simulations of the shock compaction of granular tu…
Investigating the shock response of dry and water-saturated sand: Flyer-plate experiments and mesoscale simulations Open
The effect of grain size and moisture content on the dynamic response of high purity, Oklahoma #1, sand was explored by performing uniaxial planar impact experiments on samples sieved to either fine (0.075 – 0.150 mm) or coarse (0.425 – 0.…
Simulations of disk acceleration experiments Open
Hydrocode simulations demonstrated that experimental and sample features can affect detonation pressure measurements obtained from a disk acceleration experiment. Experimental features include a layer of material (e.g, air or mineral oil) …
Investigating velocity spectra at the Hugoniot state of shock loaded heterogenous materials Open
Particle velocity and stress profiles measured in planar impact experiments on heterogeneous materials have shown significant deviations about the idealized final shock state plateau in both experimental and simulated tests. These deviatio…
Dynamic compaction of yttria-stabilized zirconia with the addition of carbon-nanotubes Open
Yttria-stabilized zirconia (YSZ) is a versatile ceramic utilized for its hardness as well as thermal stability. In these experiments, carbon nanotubes (3% and 5% by weight) were added to powdered YSZ before it was statically compacted. The…
In situ characterization of projectile penetration into sand targets Open
This work presents the results from dynamic penetration experiments in which long rod projectiles were launched into Ottawa sand at velocities ranging from 90 m/s to 350 m/s. A unique aspect of these experiments was that the sand targets w…
Stress and temperature distributions of individual particles in a shock wave propagating through dry and wet sand mixtures Open
Determining stress and temperature distributions of dynamically compacted particles is of interest to the geophysical and astrological research communities. However, the researcher cannot easily observe particle interactions during a plana…