On Stability Loss of Rod Projectiles during Penetration

Abstract

Experimental data on loss of dynamic stability or longitudinal bending of rod projectiles during penetration in targets is presented together with results of theoretical investigation. Experiments were carried out using methods of direct and reverse ballistic setup for the range of velocities 400…2000 m/s. Direct ballistic setup was used for rods with elongation up to 50, and reverse - up to 100. It was shown that loss of stability happens after a certain time following the impact. For example, in an experiment with impact velocity of 700 m/s, bending was seen 70 μs from the start of the impact. The region of stable penetration was defined by the criterion of maximal elongation, for which the rods are stable during the penetration. Critical elongation for which rods penetrated without stability loss was expressed as a function of impact velocity. The suggested model for rod projectile stability during penetration yields results consistent with experimental data.