A NUMERICAL INVESTIGATION OF PENETRATION IN MULTILAYERED MATERIAL STRUCTURE SYSTEMS/

The response of multilayered ceramic/steel targets to high velocity im pact and penetration has been investigated through finite element simu lations. A multiple-plane microcracking model has been used to describ e the inelastic constitutive behavior of ceramics in the presence of d amage. The model has been integrated into the finite element code EPIC 95, which possesses contact and erosion capabilities particularly suit able for ballistic simulations. The integrated code has been used to a nalyze the depth of penetration (DOP) and interface defeat (ID) cerami c target configurations. Parametric analyses have been carried out to establish the effect of ceramic materials, target configuration design for ceramic confinement, diameter/length (d/L) ratio of the penetrato r, material erosion threshold levels and the use of a shock attenuator on the response of multilayered targets subjected to high velocity im pact. The response characteristics are established in terms of the par ameters which can be measured experimentally. The analyses show that t he integrated code is able to predict the response of ceramic targets in confirmation with experimental findings reported in the literature. The penetration process is found to be less dependent on the ceramic materials as usually assumed by most investigators. By contrast, the p enetration process is highly dependent on the multilayered configurati on and the target structural design (geometry, and boundary conditions ). From a simulation standpoint, it has been found that the erosion pa rameter plays an important role in predicting the deformation history and interaction of the penetrator with the target. These findings show that meaningful lightweight armor design can only be accomplished thr ough a combined experimental/numerical study in which relevant ballist ic materials and structures are simultaneously investigated. (C) 1998 Elsevier Science Ltd. All rights reserved.