Characterization, Modeling, and Ballistic Impact of Kevlar/Phenolic PVB Composite

A woven aramid (Kevlar (R))/polyvinyl butyral phenolic composite that is used in ballistic applications was subjected to a wide variety of characterization and ballistic impact tests. Characterization data obtained under various stress states were used to generate two different models of the composite. The first model utilized a mesoscale modeling approach. Individual Kevlar yarns, the surrounding matrix, and interfaces are all represented with separate finite elements, and each constituent is assigned its own unique material model. The second model utilizes a continuum-level user material subroutine where rules of mixtures to relate stresses and strains within the individual fiber and matrix constituents. Although this material model is much more complex than any of those used in the mesoscale model, the approach allows the composite to be represented in simulations using a simple interconnected finite element mesh. Ballistic tests utilizing various target thicknesses and projectile sizes were also conducted to obtain validation data. Simulations of these tests were conducted using both the mesoscale and continuum models, and the results were compared to velocity and deflection data from the tests. Simulation results suggest that the relatively large void content of the material (similar to 11%) has a significant effect on the resulting impact response.