PRELIMINARY PLANE WAVE STUDIES IN THE EARTH SHOCK TUBE,
BALLISTIC RESEARCH LABS ABERDEEN PROVING GROUND MD
Pagination or Media Count:
Propagation velocities of plane waves were measured on a series of shots in a three-foot diameter sand-filled tube. The experiments were run without redistribution of the sand, and further compaction occurred with each shot. The propagation velocity increased with successive shots. The stress-time and strain-time measurements at three feet from the plane wave source are given for Shot 10. The rise times of the stress and strain were so fast that the accuracy of the stress-strain plots are limited in the region of rising stress. It was felt that the stress-strain relation derived from smoothed curves might be more significant. The strain represents an average strain over 10 inches of material. The propagation velocity measured on Shot 10 was 745 feet per second. The specific gravity of the sand material was measured at about 1.8.