The optimum arrangement of the plates in a multi-layered shield

A normal impact of a three-dimensional rigid conical impactor penetrating i nto a layered shield is studied using a simplified model for an impactor-sh ield interaction. The shield consists of adjacent plates manufactured from one of two possible materials, and the total thickness of the plates manufa ctured from every material is given. It is found that advancing any plate i nside a shield in the direction of penetration causes a monotone change in the ballistic limit velocity. A criterion for increasing or decreasing of t he ballistic limit velocity, which depends on the properties of the materia ls of the layers in the shield, is determined. A maximum ballistic limit ve locity is attained for a two-layered shield without alternating the plates manufactured from different materials. (C) 1999 Elsevier Science Ltd. All r ights reserved.