Ballistic Impacts Experiments and Plastilina/Protection Systems’ Modeling

This work deals with modeling the interactions between projectile, protection and plastilina backing during a non-perforating ballistic impact. For its mechanical behavior, ballistic plastilina was considered as a fluid. A capillary rheometry analysis over a wide range of shear rates was performed to obtain its dynamic viscosity. The mechanical response of ballistic plastilina was deduced from the rheology of plasticine using a strain rate based power law formalism. Based on the spherical cavity expansion theory, it was predicted that ballistic impact is capable of generating very high strain rates behind the impacted region. An experimental study assessed the influence of the impact velocity and the rigidity of the protection on the ballistic response of plastilina blocks, depending on indentation depths of the plastilina behind the impact region. Numerical simulations of the ballistic impact response of the plastilina covered by different ballistic protections allowed the assessment of the dynamic behavior of such systems. Good correlations were obtained between experimental and numerical analysis. It turned out that indentation depths obtained numerically are generally lower than for the experimental measurements.