Consistent Constitutive Modeling of Metallic Target Penetration using Empirical, Analytical, and Numerical Penetration Models

Abstract

Using the fit for L/D = 10 projectiles penetrating steel targets, an effective flow stress (EFS) for the target can be computed for any matched pair of experimental velocity and penetration data. The so-derived empirical EFS has previously been shown to have value in analytical analysis. For numerical analysis the EFS is taken to be the stress threshold in an elastic/perfectly plastic (Von Mises) strength model. The Johnson-Cook (JC) constitutive (strength) model, also used in numerical modeling, was taken as a baseline. The numerical analyses of L/D = 10 tungsten projectiles penetrating HzB,A steel targets using JC and Von Mises/EFS strength models matched Hohler-Stilp experimental data closely in the velocity range 1,000 to 2,000 m/s. Using the EFS in empirical, analytical, and numerical calculations yields consistent modeling of metallic target penetration.