The way in which war is waged and the unseen risks that soldiers face have changed dramatically in recent decades. Blast-induced traumatic brain injuries (TBIs) have become a signature wound of modern warfare. Since it began maintaining data on this type of injury in 2000, the Defense and Veterans Brain Injury Center’s records show that 375,230 soldiers have been diagnosed with a form of TBI, which is defined as mild, moderate or severe based on the nature of the injury.
Helping protect those who protect us has become the focus for many, including researchers from the University of Maryland School of Medicine (UMSOM) and the University of Maryland A. James Clark School of Engineering. The team’s research has led to the development of materials and a vehicle frame design that can reduce injury caused by under-vehicle explosions.
“This is the only research to date to model the effects of under-vehicle blasts on the occupants,” said Gary Fiskum, M. Jane Matjasko professor for research and vice-chair of anesthesiology at UMSOM. “We have produced new and detailed insights into the causes of TBI experienced by vehicle occupants, even in the absence of significant ambient pressure changes.”
The team developed a small-scale model of under-vehicle explosions and used it to demonstrate how different frame designs affect loads emitted from an explosive onto a vehicle. They included a double V-shaped hull—a mine-resistant armor protected (MRAP) vehicle incorporated by the U.S. military in 2007 to reduce an explosion’s ability to penetrate vehicle hulls.
Experiments tested the ability of unique, acceleration-absorbing frame designs to reduce the g-force transmitted to lab rats. During testing, five uncoated or polyurea-coated, crushable aluminum cylinders were placed between the top and bottom platforms to mitigate force transduction between the bottom and top platforms. This video shows how the effects of a blast are slowed by the shock-absorbing cylinders, which are in located between two plates that represent the hull and floorboard of a vehicle.
Using this model, the researchers tested the hypothesis that neurological affects, such as TBI, could be mitigated by the frame’s design in reducing acceleration experienced by the rats. The team performed numerous tests with coated and uncoated cylinders, which produced some success in reducing acceleration and the mortality rate of the rats, but the researchers weren’t satisfied with the results.
When they completed a test with coated cylinders and added an elastomer with a high capacity for rapid compression and decompression in response to acceleration, the team achieved success. The use of polyurea-coated cylinders in the cylinder frame reduced acceleration by 77 percent, providing near complete protection against brain injury and eliminating mortality.
The team doesn’t plan to stop its work anytime soon. It is fine-tuning the elastomeric frame design and hopes to reduce acceleration by 90 percent. If the team can achieve this goal, not only could this work potentially prevent brain injuries caused by an explosion, but it could also prevent such injuries that result from impact within a vehicle.
For more future military tech, check out Engineering the Soldiers of Tomorrow.