Citation

Jordan JB, Naito CJ. Int. J. Impact Eng. 2010; 37(5): 530-536.

Copyright

(Copyright © 2010, Elsevier Publishing)

DOI

10.1016/j.ijimpeng.2009.11.002

PMID

unavailable

Abstract

When conducting fragmentation resistance tests of armor and protective structures it is important to understand the complete nature of any fragments completely perforating the materials under test. In order to assess the lethality of a fragment after interaction with a protective structure the mass and the residual velocity must be known. Obtaining the mass of these recovered fragments is a simple matter. Determining the velocity of multiple fragments coming off a mortar or rocket is routinely done in arena characterization tests. However, determining the velocity of the fragments after interaction with the armor or construction materials is much more difficult. One method that can be used is to calibrate the velocity as a function of depth of penetration into a recovery media and the fragment mass.Cellulosic fiberboard is commonly used as a recovery media. This material is available in adequate size at an economical cost making it ideal for fragment recovery. Depth of penetration experiments were conducted with fragment simulating projectiles launched into Celotex® in order to develop an equation for the strike velocity as a function of the FSP mass and the depth of penetration into Celotex® recovery media. A powder gun launched FSPs, designed in accordance with STANAG-2920 [NATO STANAG-2920 Ballistic Test Method for Personal Armour Materials and Combat Clothing, 2nd ed., 1999.] weighing between 0.13 g and 53.78 g at striking velocities between 198 m/s and 1524 m/s. A multiple linear regression analysis was used to determine an empirical relationship for the strike velocity to the impact parameters of depth of penetration, fragment mass, and mean presented area. Sabot launched natural fragments weighing between 2.8 g and 15.8 g at striking velocities between 532 m/s and 1084 m/s were used to validate the equation.