Effects of Scale on the Performance of Whipple Shields for Impact Velocities Ranging from 7 to 10 km/s

The results of 28 hypervelocity impact tests performed using a full-scale and two subscale versions of a simple Whipple shield and aluminum spheres are presented. “Pass/Fail” lines were developed for each subscale shield for impact velocities ranging from 6.90 to 9.77 km/s. These lines were compared to one another and to a scale-appropriate ballistic limit curve generated using Ballistic Limit Equations (BLE) from Christiansen. Both subscale shields exhibited similar performance capabilities when the impact velocity was near 7 km/s. The Christiansen BLE closely described the capability of a 0.46-scale shield but underpredicted the capability of a 0.25-scale shield, which improved when compared to the ballistic limit curve, as the impact velocity was increased. The performance of the full- scale shield was significantly below its predicted capability when the impact velocity was 7 km/s.