Penetration of a rigid projectile into a multi-layered target: Theory and numerical computations

The main objective of the present work is to develop an adequate analytical model for penetration of multi-layered targets by rigid projectiles. The theoretical approach presented here generalizes the single-layer models described in [1,2]. As in [1,2] an analytical solution is developed for which the momentum equation is satisfied pointwise in the target region, while the boundary and continuity conditions are satisfied only approximately. Also, a single particular velocity field is assumed for all target layers. The predictions of the analytical solution are compared with numerical simulations obtained using the hydrocode Autodyn2D. Attention is focused on two cases of a two-layered target: one consisting of materials which differ only by their hardnesses (yield strengths); and the other consisting of significantly different materials (RHA and Aluminum). The predictions of the analytical model are in reasonably good agreement with those of Autodyn2D for both cases, independently of whether the hard layer is first or second. It should also be mentioned that the computational time is reduced from several hours for Autodyn2D to only a few minutes for the analytical model.