Soft Armor Non-Destructive Evaluation Test Method: Vibration Energy SignatureTest (VEST)

The purpose of this award is to fund a proof-of-concept demonstration of the Vibration Energy Signature Test (VEST). VEST was the winning concept resulting from the Fiscal Year 2012 NIJ Body Armor Challenge. The Challenge sought viable solutions to determine whether an individual in-service body armor has maintained an acceptable level of ballistic performance to a high degree of certainty at any point during its service life and in a manner that does not render it unfit for continued use. The ballistic performance of an armor may vary because of differences in normal daily wear and tear, other environmental factors, and the intrinsic chemical or physical properties of the ballistic materials from which it is constructed. Ideally, because the safety of officers is the ultimate priority, the service life of a vest should be determined based on its actual ballistic performance, rather than on a general warranty. The VEST concept appears to offer the potential for providing that capability. The proposed VEST test apparatus consists of a fast response quartz load cell sandwiched between a rigid test base and the shoot pack test fixture. Force signals from a test hammer and test frame load cell will be simultaneously collected with a data acquisition system which would allow a computer to deduce the delay time between hammer impact and the quartz load cell response, the shape of the force-time degradation in the quartz load cell, and the modal response from the fabric. All three of these experimental values may provide an adequate testing criterion describing the fabric stiffness which governs the body armor ballistic performance. nca/ncf