Accession Number : AD0728106

Title :   Correlation between Measured and Calculated Decelerations for a Honeycomb Energy Absorption System,

Corporate Author : HARRY DIAMOND LABS WASHINGTON D C

Personal Author(s) : Lanigan,D.

Report Date : JUL 1971

Pagination or Media Count : 25

Abstract : The correlation between measured and calculated deceleration of a projectile impacting aluminum honeycomb within a rotating tube was investigated. A piezoelectric accelerometer mounted on the projectile measured deceleration directly. The deceleration was also calculated from values of projectile impact velocity, projectile mass, target mass, and target dimensional change. It was found that when the honeycomb was located no more than an inch from the entrance to the rotating tube, the maximum percentage difference between the measured and calculated deceleration was 9.4 percent. The mean percentage difference was 0.7 percent and the standard deviation was 4.5 percent. The marked disagreement between measured and calculated decelerations when the target was placed further than one inch from the tube entrance is attributed to the fact that the air trapped between the projectile and the target slowed the projectile prior to impact, so that the projectile velocity used in the calculation was too high. Neither precrushing the honeycomb, nor changing the rotational speed of the tube affected the observed agreement. (Author)

Descriptors :   (*HONEYCOMB CORES, TERMINAL BALLISTICS), (*PROJECTILES, TARGETS), (*ARTILLERY, SIMULATORS), SANDWICH CONSTRUCTION, ACCELEROMETERS, PIEZOELECTRIC GAGES, MEASUREMENT, IMPACT, KINETIC ENERGY, COMPRESSIVE PROPERTIES, TEST METHODS

Subject Categories : Test Facilities, Equipment and Methods
      Guns
      Ballistics

Distribution Statement : APPROVED FOR PUBLIC RELEASE