Projectile penetration into mortar targets with a broad range of striking velocities: Test and analyses

Eighteen shots of flat nosed cylindrical 45# steel projectiles penetrating into mortar targets with cubic compressive strength of 50 MPa are conducted, where the striking velocities are ranged from 510 m/s to 1850 m/s. By examining the damages of targets, linear dependences of the cratering diameter and depth on the initial striking velocity, as well as the cratering volume on the initial kinetic energy of projectile are found. Three penetration regimes, i.e., rigid projectile penetration, deforming projectile penetration without eroding and eroding projectile penetration are observed successively with the increase of striking velocity. Furthermore, the experimental depths of penetration are compared with the predictions of our recently established rigid and eroding penetration models based on an extended dynamic cavity expansion model (Kong et al. 2017). The rigid projectile penetration model is further validated, and the eroding projectile penetration model is further justified, improved and validated by considering the succeeding rigid penetration stage. Finally, the analytical expressions for the upper limit velocity of rigid projectile penetration and the lower limit velocity of eroding projectile penetration are given and validated, respectively.