Rigid

Little information is published in the open literature on the nondestructive post-impact evaluation of ballistic impact damage in body armor. Traditionally, digital radiography, DR, is used to inspect ceramic body armor plates for internal defects or flaws during the manufacturing process as part of the quality assurance, QA, procedures. The DR inspection is a projection technique where the “density” of included features within the entire plate bulk thickness is projected onto a 2-D image with little ability for through thickness depth discrimination. While DR is a fairly rapid nondestructive inspection technique for QA purposes, it lacks the volumetric resolution, contrast, and depth discrimination capabilities frequently required in the terminal ballistics research activities of the authors. In the present work, the authors conducted a non-invasive interrogation and diagnostic assessment of an impacted B4C ceramic body armor plate bonded to a fiber reinforced polymer backing plate using 3-D x-ray computed tomography, XCT. This novel XCT damage diagnostic approach has been used previously by the authors and their associates for the diagnostics and analysis of ballistic impact damage in various metallic and/or ceramic laboratory terminal ballistic targets. The prior ballistic testing consisted of three individual shots with an NIJ Level III ball round. The XCT scanning was conducted on a 420keV BIR© machine.
Results of the ballistic impact damage analysis reveal multiple features of interest including the front and the rear surface damage of the B4C plate accomplished without requiring the physical removal of the composite backing plate. Substantial ceramic fragmentation, irregularly shaped impact cavities, and multiple cracks are found in the ceramic plate. Interfacial separation between the ceramic and the composite backing plate is observed adjacent to the locations of the 3 ballistic impacts. Multiple small residual projectile fragments are observed embedded primarily in the composite backing plate. Some ceramic fragmentation is also observed in the composite backing plate. Finally, substantial rear surface bulging with indications of some through perforation is observed on the composite backing plate beneath each of the three impact locations.