S&T research team develops method to test insensitive explosives

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On March 2, 2023


Dr. Catherine Johnson, center, the Robert H. Quenon Associate Professor of Mining Engineering, is working with undergraduate chemical engineering student Isabella Kestle on research to improve the process of evaluating the sensitivity of certain types of explosives. Photo by Michael Pierce, Missouri S&T.

The goal of developing new explosives is often to enhance their performance by increasing key metrics such as pressure and velocity of detonation while simultaneously decreasing their ability to be initiated, in order to reduce the likelihood of accidental initiation. Reducing that likelihood makes their manufacture, storage and transport safer.

With the aim of helping make those processes safer, a Missouri S&T student is working with a leading explosives engineering expert to evaluate the sensitivity of explosives.

“The goal of our work is to make an easier, safer, and more affordable way to evaluate the sensitivity of explosives,” says Isabella Kestle, a first-year student from Rolla, Missouri, who is majoring in chemical engineering with a minor in global economic structures. She is conducting research under the supervision of Dr. Catherine Johnson, the Robert H. Quenon Associate Professor of Mining Engineering.

The data garnered by using traditional methods to test how impact-sensitive an explosive is is limited for explosives categorized as insensitive.  To address this limitation, a new method has been developed in which the fragmentation from a small explosive charge encased in metal initiates a reaction from the high velocity metal fragments that are created as the metal casing breaks apart from reaction inside. 

To evaluate the sensitivity of the explosives, the velocity and mass of the fragments must be known. To accomplish this a high-speed camera was used to document the fragmentation pieces impacting the test sample. Velocity can be measured from the video.

“The development of new explosives is an exciting chemical process I find very interesting,” says Kestle. “The Missouri S&T Energetics Team is working towards making explosives safer, and my experience as their undergraduate research assistant has been a fun and rewarding learning experience.” 

Kestle’s path to engineering at S&T was relatively short: She attended Rolla High School, just a few blocks from the university. The daughter of an engineer, Kestle says she was intimidated by the field until her senior year, when her father complimented her ability to analyze and explain the level of chlorine in the swimming pool. With a new idea of what her future might look like, while still in high school, she enrolled in a course at S&T that introduced students to careers in engineering and computing that included guest lecturers from each department. One of those guest lecturers was Johnson.

“Dr. Johnson was so smart, and I loved how she was able to communicate her brilliance,” Kestle recalls. “I didn’t quite get the math at the time, but I could see where she was going with it.”

Kestle emailed Johnson, who invited her to S&T’s Experimental Mine, where Johnson demonstrated and explained primary and secondary explosives. Then, although it’s outside her major, Kestle got busy learning as much as she could about explosives and applied for a job on Johnson’s research team. The experience, she says, has provided the opportunity to learn about another field of engineering and to more deeply explore her love of creativity and problem solving.

“High school was a task-based adventure, but S&T is a passion-based adventure,” she says. “I’m doing exactly what I want to do.”

About Missouri University of Science and Technology

Missouri University of Science and Technology (Missouri S&T) is a STEM-focused research university of over 7,000 students. Part of the four-campus University of Missouri System and located in Rolla, Missouri, Missouri S&T offers 101 degrees in 40 areas of study and is among the nation’s top 10 universities for return on investment, according to Business Insider. For more information about Missouri S&T, visit www.mst.edu.

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