  Finite element method (FEM) suffers from a serious mesh distortion problem
when used for high velocity impact analyses. The smooth particle hydrodynamics
(SPH) method is appropriate for this class of problems involving severe damages
but at considerable computational cost. It is beneficial if the latter is
adopted only in severely distorted regions and FEM further away. The coupled
smooth particle hydrodynamics - finite element method (SFM) has been adopted in
a commercial hydrocode LS-DYNA to study the perforation of Weldox 460E steel
and AA5083-H116 aluminum plates with varying thicknesses and various projectile
nose geometries including blunt, conical and ogival noses. Effects of the SPH
domain size and particle density are studied considering the friction effect
between the projectile and the target materials. The simulated residual
velocities and the ballistic limit velocities from the SFM agree well with the
published experimental data. The study shows that SFM is able to emulate the
same failure mechanisms of the steel and aluminum plates as observed in various
experimental investigations for initial impact velocity of 170 m/s and higher.
