Analysis of the Mechanics of Preforation by Projectiles

To explain the mechanics of perforation of thick metallic target plates a modified version of the analysis suggested by Awerbuch and Bodner [2] is given by a cylindrical projectile. Although the analysis retains the basic concept of the perforation process to occur in three stages as was assumed by Awerbuch and Bodner [2] a new explanation, as to the cause and effect of the compressive force is suggested. Attention is also drawn to the force required to cause internal plastic deformation of the target material, during the passage of the projectile. In addition, the mass of the target material ahead of the projectile is modified in the manner of Tate [17]. The analysis retains the initial entrance diameter to be the same as that of the projectile, at the instant the projectile hits the target and assumes that the final length of the plug is attained at the end of the process instead of at the beginning of the second stage. The computed results using the modified analysis yield better agreement with the experiments for the perforation process especially for plates whose thicknesses are between 1 and 2.5 times the projectile diameter.