Comparing the Backface Deformation Behavior between Soft and Hard Body Armors

Abstract

Hard and soft body armor employ different mechanisms for defeating the incoming threat; however test standards for evaluating both types of body armor systems use the same metric with regards to backface deformation (BFD). To understand the limitations of using the same metric for BFD, it is important to understand the backface signatures for both types, and where the signatures overlap and differ. Using a thoracic rig designed to measure the dynamic behavior of the BFD, the depth, strain rate, velocity, and diameter of deformation were examined behind hard and soft armors. Generally, the hard armor had greater depths and rates of deformation than the soft armor systems. Ballistic conditions that resulted in similar BFD behaviors in the hard and soft armors were identified. By identifying conditions that result in similar deformation behaviors, further research can be performed to determine if these conditions result in similar injuries.