PENETRATION OF A LONG ROD INTO A SEMI-INFINITE METALLIC TARGET AT HIGH VELOCITY

Abstract

The one-dimensional hydrodynamic theory proposed by Tate [1.2] is considered as a standard reference for describing the penetration of long rods into semi-infinite metallic targets. In this paper, a modified analytical approach using Tate's theory has been developed, wherein the penetration process is considered to consist of three phases: hydrodynamic, deformation and rigid. These phases are related to the situations of the rod front during target penetration. For each rod phase, the target penetration is described consisting of two stages: erosion and deformation. The plastic wave theory is used with the equations of motion to predict the sequence of penetration stages that associate with each rod penetration phase and represent the complete penetration process. In addition, the strength factors for both rod and target materials, respectively, are assumed not to vary during their erosion. The governing equations of the analytical approach are programmed using FORTRAN. The input data consist of rod impact velocity, length, diameter, density and Brinell hardness number as well as target density. Young's modulus and Brinell hardness number. The present results are concerned with the predictions of the produced hole diameter and penetration depth in semi-infinite targets due to their impact by long rods with high velocities. The predicted results are compared with the experimental results of other investigators: good agreement is obtained. Moreover, the program is used to discuss the influence of the different penetration parameters on penetration depth and produced hole diameter.