Author(s)

J Leppänen & K Gylltoft

Abstract

When a projectile impacts a concrete target, it penetrates the concrete, severe crushing occurs and a crater forms. When concrete is subjected to impact loading, the strength will increase due to the strain rate and confinement effects. This paper presents finite element analyses of concrete perforation with a steel projectile. To predict the perforation depth of the projectile and the crater size of the concrete, material models are required where the strain rate effect, large deformations and triaxial stress states are taken into account. By using the Lagrangian technique, large deformations will lead to excessive grid distortions and tangling; therefore an erosion algorithm is needed. By using the Eulerian technique, the problems of grid tangling are overcome. The analyses are performed with the nonlinear finite element program AUTODYN and the results are compared to experiments concerning the depth of penetration and the crater diameter.

Keywords