Comment on “The effect of target inertia on the penetration of aluminum targets by rigid ogive-nosed long rods” (Int J Impact Eng 2016; 91: 6-13)

Abstract

In a recent paper [1] , we present closed-form, penetration equations for rigid, ogive-nose projectiles that penetrate aluminum targets. The final depth of penetration equation was derived from the spherical cavity-expansion approximation, and modeled the target as incompressible with power-law strain hardening with, and without target inertia. These target material models neglect compressibility and strain-rate effects, which as shown in [2] , for power-law strain hardening 6061-T6511 aluminum targets the radial stress at the cavity surface that assumes compressibility and strain-rate effects gives results very close to the incompressible model with power-law strain hardening without strain-rate effects for the expansion velocities considered. Predictions in [1] from the simplified model including target inertia are in excellent agreement with penetration data for ψ =3.0 and 1/2 caliber-radius-head (CRH) long rod projectiles that penetrate 6061-T651 aluminum targets for striking velocities to 1800m/s. The simplified dynamic spherical cavity-expansion approximation model in [1] contains terms related