Analytical Processes for Predicting Nanosecond Response of Highly Rate-Sensitive Materials

Ballistic and blast protection of both the crew and vital equipment onboard U.S. Navy surface ships and carriers is a critical component in the design of topside structures on these vessels. Materials such as glass, Plexiglas and polyurea are being considered and implemented for protection in these applications due to their low density and inherent damage mechanisms which absorb large amounts of energy under high-velocity impact or blast loading conditions. Likewise, these material systems are being used in layered or laminated configurations to exploit the benefits of each individual material. However, the ability to numerically simulate these materials constitutive and damage behavior does not readily exist in traditional analysis tools. Therefore, for this effort we have proposed to utilize and implement three new constitutive material models for conventional glass, PMMA, and polyurea/polyurethane. The material models will initially be implemented within the shock hydrocode CTH and will allow for more accurate simulation of ballistic impact events on the material systems of interest and also offer a more efficient armor system design approach.