Ricochet of ap projectiles from hard concrete targets

Experimental and computational work was conducted in order to study and characterize the effect of ricochet of AP projectiles that interact with oblique concrete targets. In series of experiments, 14.5 mm AP projectiles were fired against hard concrete blocks (60 MPa) at 20, 25, 30, 35, 40 degrees (related to the line of fire) and muzzle velocity of 973 m/sec. HP multi-channel 150 kV flash x-ray system was employed in order to monitor the ricochet interactions between the projectiles and the targets. The problem was simulated employing the LS-DYNA and DYTRAN 3D codes. The concrete was modeled according to Holmquist-Johnson-Cook (LSDYNA) and by Mohr-Coulomb yield model (DYTRAN). The code calculations seemed to correlate well with the experimental results. Both indicate that the critical angle to achieve ricochet is at the range of 35° to 40° and that the exit velocities decrease when impact angels increase.