CAVS Researchers Invent Significant Advancement in Hopkinson Bar Technology

February 25, 2020

Stardard Dynamics MSU Collaboration
Mississippi State and REL personnel hold the MSU-developed serpentine bar technology, a significant advancement in Hopkinson bar systems. Pictured, from left, is MSU Center for Advanced Vehicular Systems Associate Director Hongjoo Rhee, REL Co-owner Adam Loukus, Associate Professor of Mechanical Engineering Haitham El Kadiri, REL Engineer Luke Luskin, Assistant Professor of Mechanical Engineering Wilburn Whittington, REL President Josh Loukus, mechanical engineering doctoral student Trey Leonard of Madison, Alabama, and mechanical engineering undergraduate student Billy Zhang of Starkville.
Mississippi State University researchers have patented and licensed a major advancement in split Hopkinson pressure bar technology, significantly reducing the amount of space needed for intermediate and high-strain rate testing.

While conducting research on infant head trauma, researchers at MSU’s Center for Advanced Vehicular Systems needed a way to conduct impact testing with biological materials. While a traditional Hopkinson bar system, an apparatus commonly used for testing impact and strain on materials, would have worked, it would have taken up hundreds of feet in length—space that was not available at the bustling research center. However, CAVS engineer Wilburn Whittington, with the support of colleagues Haitham El Kadiri and Hongjoo Rhee, was able to prototype a serpentine bar that can accomplish the same task in only 20 feet of space.

Whittington is an assistant professor in MSU’s Department of Mechanical Engineering. El Kadiri is an associate professor in the Department of Mechanical Engineering and holds the Coleman-Whiteside Professorship. Rhee is an associate professor at the same department and is an associate director at CAVS.

“We’ve already used this product in our work for the military, national labs, and automotive companies,” said Whittington. “This has tremendous potential for universities and laboratories, as well as any company making materials or looking at crash testing and other tests like that.”

After the research team patented the new technology, it gained interest from the scientific community and REL, a Michigan-based manufacturer that makes and sells Hopkinson bar systems. Working with MSU’s Office of Technology Management, El Kadiri, Rhee and Whittington were able to license the serpentine bar technology to REL, which began marketing the product this week at The Minerals, Metals & Materials Society annual conference in San Diego, California.

Whittington said the serpentine bar can be used as a new product and also used to enhance old products, making shorter Hopkinson bar systems capable of conducting tests that previously required significantly more space. He noted that in labs that conduct high-speed tests with radioactive materials, these materials must be handled in specialized rooms, which puts space at a premium.

“People test things like explosives and armor on these systems,” Whittington said. “Like with biological materials, these labs have to be specialized, so a serpentine bar gives them more testing abilities.”

El Kadiri, Rhee, and Whittington were able to commercialize their invention through a Mississippi University Research Agreement, which allowed them to form a private company to market the technology, Standard Dynamics, LLC. In addition to showcasing the technology in San Diego this week, MSU and REL personnel will highlight the serpentine bar at the Society of Experimental Mechanics annual conference this summer in Orlando, Florida.

For more on the Office of Technology Management, visit www.otm.msstate.edu.

MSU is Mississippi’s leading university, available online at www.msstate.edu.

Written by James Carskadon