Accession Number : AD0860078

Title :   Spall Studies on 6061-T6 Aluminum.

Descriptive Note : Technical rept. Jan 68-Mar 69,

Corporate Author : AIR FORCE WEAPONS LAB KIRTLAND AFB NM

Personal Author(s) : Jajosky, Charles, Jr. ; Ferdman, Mark A.

Report Date : SEP 1969

Pagination or Media Count : 92

Abstract : Flat specimens of 32 mil 6061-T6 aluminum were dynamically shock loaded by high velocity Mylar flyer plates. A 16 kilojoule capacitor discharge system and exploding foil assemblies were used to accelerate 3, 5, 7.5, and 10 mil Mylar flyers at spall threshold velocities between 0.5 and 2 mm/microsec. The environment between flyer and target was both normal and atmospheric air and vacuum. The observed apparent spall threshold and spall depths in air differed significantly from those obtained in vacuum. The air layer has the effect of reducing the amplitude of the induced stress pulse and spreading the shock front and/or its pulse duration. The spall threshold data were analyzed and an attempt was made to apply available predictive models. The data best fit the Tuler, et al., model, with a stress exponent of 1.8. This condition very closely approximates a pure-energy criterion for spallation. (Author)

Descriptors :   (*REENTRY VEHICLES, NUCLEAR EXPLOSIONS), (*AIRFRAMES, NUCLEAR EXPLOSION DAMAGE), (*ALUMINUM ALLOYS, FRACTURE(MECHANICS)), SIMULATION, IMPACT TESTS, CRACKS, CRACK PROPAGATION, SHOCK WAVES.

Subject Categories : Metallurgy and Metallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE