BALLISTIC EFFICIENCY OF DIFFERENT CERAMIC MATERIALS AGAINST TUNGSTEN ALLOY ROD PENETRATORS

In this paper, the analytical model developed by Riad [1] has been modified herein to describe the penetration of a high-speed rod into a ceramic tile backed by a thick metallic plate. The present model identifies three main phases for the target penetration; these are: (i) ceramic fragmentation, (ii) penetration into fragmented ceramic, and (iii) penetration into thick back plate. Phase (i) consists of a single stage, whereas each of the other two phases consists mainly of two penetration stages. Two modes are considered to be associated with the rod and thick back plate during penetration process; these are erosion and rigidity. The main equations representing each penetration stage are introduced. The current penetration stage is ascertained according to the relative velocity between the rod mass and mass of ceramic or thick back plate in contact with the rod front. Moreover, the present model is adapted to describe the penetration of such a rod into thick back plate only by setting the thickness of ceramic tile equal to zero. The present model is capable of predicting the time histories of the velocities of moving masses and the rod penetration depth through ceramic/metal and thick metallic targets, respectively. For the penetration of thick steel plate, the essential dependence of its flow stress on deformation rate is considered. In addition, the matching of predicted results of the present model with the corresponding experimental measurements of Reaugh et al. [2] serves for the determination of the flow stress of ceramic globally. The present results are concerned with the determination of ballistic efficiencies of different ceramic materials based on the predicted residual penetration depth into a thick steel backing. The influence of ceramic strength, thickness and rod impact velocity on the ballistic mass efficiency of ceramic is presented and discussed.