PROJECTILE DAMAGE IN STRESSED PLATES.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING
Pagination or Media Count:
Targets consisting of 7075 T-6 aluminum with a thickness of 0.190 in. were impacted by 7.62 mm and 0.50 cal. projectiles at impact velocities from 800 to 2800 fps. Tensile pre-stresses up to 30,000 psi were applied to the targets in a direction normal to the visible grain orientation of the material. Impact angle was varied from 0 degrees normal to 60 degrees. The first catastrophic failures caused by crack propagation occurred at 20,000 and 10,000 psi for the 7.62 mm and 0.50 cal. projectiles, respectively. An increase in pre-stress had no effect on the energy or momentum loss of the projectile. The maximum damage occurred at the minimum perforation velocity. The velocity range over which target failure due to crack propagation occurred was seen to increase with an increase in prestress. Author
- Metallurgy and Metallography