A plastic wave model for the perforation of a finite metal plate struck by a flat-ended projectile

Abstract

A theoretical study is presented herein on the perforation of a finite metal plate struck by a flat-nosed projectile at normal incidence. Projectile deformations and plug formation are analyzed using plastic wave theory. Three modes of perforation (namely, perforation by a rigid projectile, perforation by a deformable projectile and perforation by an erosive projectile) are studied theoretically. Furthermore, a two-stage adiabatic shear model is introduced to describe the instability of adiabatic shear during the perforation process. Various equations are established and the critical conditions for the transition among the three modes are determined. It transpires that the present model predictions are in good agreement with the available experimental data for Weldox 460E steel plates struck transversely by flat-ended projectiles in terms of ballistic limit, residual velocity, transition temperature, projectile residual diameter, projectile residual length and plug thickness.