Debris cloud characterization at impact velocities of 5 to 11 km/s

Abstract

A series of experiments has been performed on the Sandia Hypervelocity Launcher to impact a 1.25‐mm thick aluminum bumper by an aluminium flier plate 17‐mm diameter by 0.092‐mm thick over the velocity range of 5 km/s to 11 km/s. Radiographic techniques were employed to record the debris cloud generated upon impact. The shape of the debris cloud is found to depend on the flier plate tilt. Generally—the data indicate a central core of high desity surrounded by a diffused layer. These experiments allow measurements of debris cloud expansion velocities as the material undergoes a phase change from solid fragments at impact velocities of 5 km/s to a mixture of liquid and vapor phase at higher impact velocities. The expansion velocity of the debris cloud increases with increasing impact velocity, with the high‐density leading edge traveling faster than the impact velocity. There is a difference between the X‐ray and photographic measurements of expansion velocities at higher impact velocities. This is believed to be due to the presence of very low‐density vapor in the photographic records that are not detected using X‐ray techniques.