Abstract : Numerical simulations of ballistic impact and penetration by tungsten rods into targets consisting of layers of aluminum nitride ceramic tile(s), polymer laminae, and aluminum backing are conducted over a range of impact velocities on the order of 1.0 to 1.2 km/s. Results for ballistic efficiency are compared with experimental data from the literature. Predicted residual penetration depths tend to exceed corresponding experimental values, though simulations and experiments both demonstrate a trend of decreasing efficiency with increasing impact velocity. Closest agreement is obtained when polymer interfaces are not explicitly represented, suggesting the current model representation of such interfaces is overly compliant. Results emphasize the importance of proper resolution of geometry and constitutive properties of thin layers and interfaces between components for accurate numerical evaluation of performance of modern composite protection systems.