Triaxial Acceleration Measurement for Oblique Penetration of a Rigid Projectile into Concrete Target

In order to obtain accurate data of motion parameters of a rigid projectile during the oblique penetration event, a triaxial acceleration measurement device (TAMD) was developed and a unique calibration method was developed by using a pneumatic gun and two sets of grating laser Doppler interferometers. A set of penetration experiments into concrete targets with average compressive strengths of 35 and 45 MPa were conducted. The 96-mm-diameter, 630-mm-long, ogive-nose projectiles were machined from 35CrMnSiA steel and designed to contain a TAMD in the tail of the cavity. The projectiles were launched by a 100-mm-diameter, smooth-bore powder gun to striking velocities between 300 and 500 m/s and impacted the concrete target at an oblique angle of 0 to 30 degrees. The acceleration during the launch and the triaxial deceleration during the penetration were recorded successfully by the TAMD. When the oblique angle changed slightly with time, the single and double integrations of axial deceleration versus time revealed accurate concurrence with the measured striking velocity and the penetration depth, respectively.