Mechanism of high-velocity projectile penetration into concrete

The penetration depth of rigid projectiles is investigated using the modified spherical cavity expansion theory and the Holmquist-Johnson-Cook (HJC) model for the concrete targets, in which the model parameters used in the Mohr-Coulomb Tresca-limit yield criterion are obtained by the triaxial compression tests. By comparing the cavity expansion pressures of the concrete samples with two different types of aggregate, the influence of the aggregate hardness on the penetration processes is discussed. With the analysis of the tractions acted on the projectile nose, the influences of the projectile and target material properties as well as the projectile structure on the transition impact velocity are also discussed. By comparing the theoretical results with the experimental data, two penetration mechanisms are demonstrated for the ogive-nose projectile penetration into concrete with the striking velocities up to 2.0 km/s.