Accession Number : ADA211189

Title :   Structural Degradation of High Performance Armor.

Descriptive Note : Final rept.,

Corporate Author : ARMY LAB COMMAND WATERTOWN MA MATERIAL TECHNOLOGY LAB

Personal Author(s) : Cowie, John G. ; Azrin, Morris ; Kula, Eric B. ; Ripling, Edward J.

Report Date : APR 1989

Pagination or Media Count : 20

Abstract : Conventional ballistic evaluation of armor plate is based on a critical impact velocity for penetration. At high hardness levels and/or low temperatures, ballistic impact can give rist to extensive plate cracking, resulting in structural degradation whether or not penetration occurs. This report provides preliminary results on a test procedure to assess the plate cracking sensitivity of high strength, steel armor plate. The procedure involves the production of a large flaw, or crack starter, at the center of a plate and then impacting the center of the opposite face with a soft, blunt-nosed projectile. The impact tests are performed over a range of temperatures to yield a plate shatter transition temperature (PSTT). The PSTT is simply the highest plast temperature at which extensive plate cracking occurs. The influence of PSTT test parameters and correlation with crack arrest fracture toughness over the same temperature range are currently being studied. (sdw)

Descriptors :   *ARMOR PLATE, *CRACK PROPAGATION, *FRACTURE(MECHANICS), ARRESTING(PROCESS), BALLISTICS, BLUNT BODIES, CRACKS, DEFECTS(MATERIALS), DEGRADATION, HARDNESS, HIGH STRENGTH, IMPACT, IMPACT TESTS, LEVEL(QUANTITY), LOW TEMPERATURE, METAL PLATES, NOSES, PRODUCTION, PROJECTILES, RANGE(EXTREMES), STEEL, STRUCTURAL PROPERTIES, TEMPERATURE, TEST METHODS, TOUGHNESS, TRANSITION TEMPERATURE, VELOCITY, YIELD, PENETRATION.

Subject Categories : Armor
      Metallurgy and Metallography
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE