Concrete penetration by eroding projectiles: Experiments and analysis

Spherical-nose copper and tantalum rods with aspect ratios between 4.0 and 14.6 were gun launched against 91-cm-diameter and 91-cm-long concrete and simulant reinforced-concrete targets with velocities ranging from 0.15 cm/mu s to 0.19 cm/mu s. Targets were instrumented with a sequence of break gauges that provided valuable data for characterizing the penetration process. Target-hole profiles and projectile residual masses were measured and reported. Analysis of the penetration performance of projectiles was performed within the framework of the modified hydrodynamic theory of pen'etration. Based on the results of these calculations, the penetration efficiencies of the copper and the tantalum projectiles were compared as functions of impact velocities. Analysis of the penetration resistance of the simulant reinforced-concrete targets was based on treating the targets as ''composites,'' comprised of layers of concrete proper and reinforcing steel; the results of these calculations were compared with the experimental data. Using this theory, the penetration resistance of a concrete/steel/concrete ''composite'' was investigated as a function of the following parameters: thickness of the surface layer of the concrete, thickness of the steel reinforcement, and impact velocity.