Emily Johnson, a doctoral candidate in explosives engineering, will defend their dissertation titled “Investigating Detonation Parameters through the Plate Dent Test: A Novel Approach for Characterizing Detonation Curvature and Thickness.” Their advisor, Dr. Catherine Johnson, is a Robert H. Quenon Associate Professor of Mining Engineering in the mining and explosives engineering department. The dissertation abstract is provided below.

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 to provide an alternate, simple and inexpensive, method of measurement. The first of these studies focuses on the Gurney Model and demonstrated that its ability to accurately characterize explosive output was limited by scale. For small explosive charges, the accuracy of the model was diminished by charge casing material strength, length to diameter ratio of the charge, and by the charge to casing mass ratio. Given these conclusions, simulation was employed, to understand how varying these characteristics affects the detonation wave itself. It was found that well established principles about energy loss in a detonation wave due to charge diameter and material casing volume, were impacted by casing material characteristics, like density, sound speed, and tensile strength. With a desire to measure these effects experimentally, the plate dent test, traditionally used to measure detonation pressure, was introduced. A series of studies were conducted to identify the potential for the plate dent test to measure both casing material and detonation wave characteristics. The first of these studies demonstrated repeatability and measurable uniqueness when only casing material was varied. The second developed regression fit equations that could correlate the dents to detonation velocity, impulse, and curvature. The final study adapted these relationships for varied casing thickness and charge diameters. This dissertation demonstrates the ability of the plate dent test to fully characterize an explosive’s detonation performance to within 15% accuracy.