Accession Number : ADA325977

Title :   Deformation of a Coarse-Aggregate Barrier Subjected to Ballistic Impact Loading.

Descriptive Note : Final rept. Aug 94-Dec 95,

Corporate Author : ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Bjerke, Todd W.

PDF Url : ADA325977

Report Date : APR 1997

Pagination or Media Count : 33

Abstract : An experiment-oriented investigation aimed at gaining insight and understanding of the physical phenomena that occur when a projectile impacts a thin barrier consisting of a uniform, coarse aggregate was performed at the U.S. Army Research Laboratory. The thin barrier target was an assembly of solid steel cylinders oriented in a 15-by-15 rod square-packed array. Each cylinder had a length-to-diameter ratio of 3.5 and a serial number imprinted on its rear surface to permit barrier reconstruction after each shot. The projectile consisted of a solid aluminum cylinder with a diameter of approximately 2.5 aggregate diameters and a length of 1.25 aggregate element lengths. The impact velocity was 2 km/s. The data collected consisted of the crater size in the barrier (obtained from post-test reconstruction), plastic deformation of individual cylinders, and the residual penetrator length. A detailed analysis of the damage inflicted on the aggregate elements of the barrier was performed. Iso-strain contours were mapped on the face of the barrier to shed insight into the contact mechanics of the aggregate elements. A semi-empirical aggregate deformation model was created. The expected influence of impact velocity on aggregate deformation has been proposed and added to the semi-empirical model.

Descriptors :   *PROJECTILES, PLASTIC DEFORMATION, VELOCITY, ARMY RESEARCH, IMPACT, SIZES(DIMENSIONS), MODELS, PHYSICAL PROPERTIES, LOADS(FORCES), DEFORMATION, SOLIDS, TARGETS, STEEL, SURFACES, MECHANICS, AGGREGATES(MATERIALS), PENETRATION, CYLINDRICAL BODIES, RESIDUALS, ALUMINUM, LENGTH, BARRIERS, THINNESS, BALLISTICS, CRATERS.

Subject Categories : Ammunition and Explosives

Distribution Statement : APPROVED FOR PUBLIC RELEASE