Correlation between Measured and Calculated Decelerations for a Honeycomb Energy Absorption System,
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1971
- Accession Number
- AD0728106
Entities
People
- D. Lanigan
Organizations
- Harry Diamond Laboratories