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Full-Text Articles in Mining Engineering

Explosive Dust Test Vessel Comparison Using Pulverized Pittsburgh Coal, Jacob Miller, Jay Schafler, Phillip R. Mulligan, Robert Eades, Kyle A. Perry, Catherine E. Johnson Oct 2018

Explosive Dust Test Vessel Comparison Using Pulverized Pittsburgh Coal, Jacob Miller, Jay Schafler, Phillip R. Mulligan, Robert Eades, Kyle A. Perry, Catherine E. Johnson

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Explosions of coal dust are a major safety concern within the coal mining industry. The explosion and subsequent fires caused by coal dust can result in significant property damage, loss of life in underground coal mines and damage to coal processing facilities. The United States Bureau of Mines conducted research on coal dust explosions until 1996 when it was dissolved. In the following years, the American Society for Testing and Materials (ASTM) developed a test standard, ASTM E1226, to provide a standard test method characterizing the “explosibility” of particulate solids of combustible materials suspended in air. The research presented herein ...


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 ...


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 ...


Percussive Penetration Of Unconsolidated Granular Media In A Laboratory Setting, Leslie S. Gertsch Feb 2007

Percussive Penetration Of Unconsolidated Granular Media In A Laboratory Setting, Leslie S. Gertsch

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

This controlled study examined the feasibility of a simple percussive approach to drilling through unconsolidated regolith deposits on Mars. The experiments showed that the approach is feasible at the low power levels and low confining pressures used, and that the rate of impact is more important to the penetration rate than is the mass of the impactor (hammer). More massive impactors tend to lower energy efficiency, as they do in terrestrial pile-driving. Unexpectedly, penetration plotted against applied energy tends to cluster into parallel linear trends. Within a given cluster, penetration is very sensitive to applied energy, while between clusters, the ...


Effect Of Water Ice Content On Excavatability Of Lunar Regolith, Leslie S. Gertsch, Robert Gustafson, Richard E. Gertsch Feb 2006

Effect Of Water Ice Content On Excavatability Of Lunar Regolith, Leslie S. Gertsch, Robert Gustafson, Richard E. Gertsch

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The amount of water ice contained within prepared samples of JSC-1 lunar regolith simulant strongly affects the excavatability of the material. As part of a NASA Phase I SBIR project, load-penetration testing of JSC-1 lunar regolith simulant was performed at water ice concentrations ranging from zero to 11% by mass (approximately saturated), after compaction and cooling to simulate probable lunar conditions. After mixing dry JSC-1 simulant with the appropriate amount of water, the samples were individually compressed into containment rings under 48 MPa of pressure. Thermocouples embedded in the samples monitored internal temperature while they were cooled in a bath ...