Numerical investigation of high strength Aluminum alloy subjected to high velocity impact by a rigid spherical projectile

The present paper deals with the numerical analysis of the impact and perforation of a high velocity rigid steel spherical projectile through an Aluminum plate AA2014-T652 using the commercial software LS-DYNA. These numerical investigations are performed in the velocity range from 800 m/s to 1300 m/s. The target plate with a thickness of 15mm and the spherical projectile with a diameter of 10mm are modelled using three-dimensional elements (3D) in a Lagrangian formulation. A hydrostatic tensile stress failure model combined with the Johnson and Cook constitutive model is used to highlight the dynamic failure of the target. The different failure mechanisms observed on the Aluminum plate from the moment of impact to full perforation are discussed. For validation purposes, the analytical model of Recht-Ipson, which relates the residual to the initial velocity and the ballistic limit velocity, is used. Moreover, the numerical results based on the crater diameter at the front and rear surface of the plate, the dimensions of the penetration channel and the thickness of the frustum shaped cavity of the plate are compared to the experimental data available in literature. A good correspondence between numerical and experimental results is found. The hydrostatic tensile stress parameter used to predict failure of the target could be considered as a fast and accurate solution for the prediction of dynamic mechanical behavior of high strength Aluminum structures.