Resistance of a concrete target to penetration of a rigid projectile - revisited

Characteristics of combined blast and fragments loading

We present an analytical approach for the penetration and perforation processes of concrete targets by rigid projectiles. We first derive an empirical relation for the penetration resistance (Rt) o...

Modeling the penetration and perforation of concrete targets by rigid projectiles

A numerical study on the influence of free water content on the ballistic performances of plain concrete targets

The influence of free water content on ballistic performances of concrete targets

We examined data from two sets of penetration experiments that recorded deceleration during penetration into concrete targets with compressive strengths of 23 and 39 MPa. The 76.2-mm-diameter, 3.0 caliber-radius-head (CRH), 13 kg projectiles were machined from 4340 Rc 45 steel and contained a single-channel, 15 kHz acceleration data recorder. The data recorder was fitted into a circular hole in the solid nose of the projectile, so during penetration the accelerometer mounted in the data recorder measured structural responses as well as rigid-body projectile deceleration. Since the deceleration data were limited to 15 kHz, higher frequency responses were not measured. Furthermore, there are no available internationally accepted calibration procedures for accelerometers. Because of these complications, we present a method to correct the deceleration data so that an integration of the deceleration data agreed with the measured striking velocity. These corrections were small, and a double integration of the corrected deceleration was in good agreement with the measured depth of penetration. In addition, we developed two empirical penetration models that described deceleration versus displacement and specific kinetic energy (kinetic energy divided by projectile mass) versus displacement for the rigid-body response of the projectile. Data and model predictions showed that the deceleration-displacement response could be closely approximated by a linear rise with a depth of two projectile diameters followed by a region with constant deceleration until the projectile came to rest. Specific kinetic energy-displacement data and model predictions showed a nearly constant slope after the entry region, and this slope is the magnitude of the constant deceleration. Predictions from both methods closely agree with each other and the deceleration data.

Evaluation of Large Amplitude Deceleration Data from Projectile Penetration into Concrete Targets

We examined data from two sets of penetration experiments that recorded deceleration during penetration into concrete targets with compressive strengths of 23 and 39 MPa. The 76.2-mm-diameter, 13 kg projectiles contained a single-channel acceleration data recorder. We plotted deceleration versus displacement data and showed that this response could be closely approximated by a linear rise region with a depth of two projectile diameters followed by a tunnel region with constant deceleration until the projectile came to rest. A new empirical model predicts accurately the deceleration-displacement responses.

M. J. Forrestal

Papers

Evaluation of Large Amplitude Deceleration Data from Projectile Penetration into Concrete Targets

Deceleration-Displacement Response for Projectiles That Penetrate Concrete Targets