Effect of Lode angle and projectile diameter on the ballistic resistance of 6061-T651 aluminum alloy plates struck by hemispherical nosed projectile

Abstract

Aluminum alloy has been gradually applied to the field of armor protection because of its excellent material properties. The research on its ballistic resistance has important theoretical and engineering application value. In order to study the ballistic resistance of 6061-T651 aluminum alloy plate, the impact tests of 6061-T651 aluminum alloy plate against hemispherical nosed projectile with a diameter of 12.66 mm were carried out with a light gas gun system and the ballistic limit velocity and failure mode of the target plate were obtained. Subsequently, the numerical simulations corresponding to the tests were carried out by using the Lode dependent and independent fracture criteria, and the effect mechanism of the Lode angle on the numerical simulation results were analyzed. Finally, the effect of projectile diameter on the ballistic resistance of the target plate was analyzed by the expansion of numerical simulation. The research results show that the numerical simulation will be quite different from the test results if the effect of the Lode angle on the material fracture strain is not considered. As the diameter of the projectile increases, the armor-piercing efficiency of the hemispherical nosed projectile is improved since the energy dissipation mechanism of the target plate gradually changes from ductile hole enlargement to shear plugging.