The Effect of Projectile Nose Geometry on the Critical Velocity and Failure Mode of Yarns Subjected to Transverse Impact

Abstract

The effect of projectile nose geometry on the resulting critical velocity and failure mechanism of high-performance yarn is explored during single yarn transverse impact. Kevlar® KM2 yarns have been shot with three different projectile nose geometries, namely 0.30-cal round, 0.30-cal fragment simulation projectiles (FSP), and razor blades, at velocities surrounding the critical velocity required to initiate immediate yarn failure. In efforts to negate effects of wave interaction, strains developed at the experimental critical velocities are compared to quasi-static experiments designed to promote similar geometric loading conditions to those created during transverse impact. Additionally, above said critical velocities, strikes with 18-mm flat disc projectiles have been performed in efforts to ascertain the location of yarn failure at the initial stages of impact using high-speed imaging.