A three-dimensional abrasion algorithm for projectile mass loss during penetration

A three-dimensional finite-element algorithm is presented for the computation of projectile mass loss due to abrasion at a projectile/target interface. The algorithm is an extension of the algorithm previously presented by the authors for axisymmetric computations. A description of the algorithm emphasizes the additional complexities introduced by three dimensions. The most significant complexity is the adjustment of the Lagrangian projectile mesh to avoid the convergence of nodes at the tip of the projectile nose as mass is removed from the nose. This adjustment is achieved in three dimensions by combining periodic calls to a rezoning algorithm (that redistributes the interior nodes of the mesh without changing connectivities) with an incremental adjustment of the surface nodes (that is applied tangent to the surface each timestep.) Numerical examples include comparisons to test data and demonstrations of the effects of non-axisymmetric impact.