Effects of projectile diameter and specimen thickness on size distribution of ejecta resulting from carbon fiber reinforced plastic plates in hypervelocity impacts

The size distributions of ejecta resulting from projectile perforation of CFRP (carbon fiber reinforced plastic) plates were examined. Size of ejecta collected from the test chamber after impact experiments were measured. The effects of projectile diameter and specimen thickness on size distribution of ejecta were examined. Penetration hole area increased with projectile diameter. The projectile diameter increased ejecta size and the number of ejecta on the impact side and rear side of targets. Most of the ejecta showed aspect ratio less than 0.2. The specimen thickness also increased ejecta size and the number of ejecta other than the projectile diameter of 1.6 mm. When the projectile diameter was 1.6 mm and the impact velocity was 3.5 km/s, the specimen thickness did not affect ejecta size and the number of ejecta. When the vertical axis of the ejecta distribution with respect to aspect ratio was divided by the number of ejecta having length over 3 mm, all results of t/d < 1 were roughly on a curve for impact side and rear side respectively. Experimental formulas for the curves were proposed. © 2018 The Society of Materials Science, Japan.