Perforation Thickness. - Continued

DOE-STD-3014-96

APPENDIX C

A ratio of 2T/D of unity corresponds to a solid steel missile.

CEA-EDF Formula (1977).

Based on an empirical fit to data from 52 tests with solid cylindrical missiles

impacting at velocities greater and less than the critical perforation velocity, the

CEA-EDF formula (Reference 7) was developed in France and presented in

1977. It gives the perforation velocity, Vp, as:

Dtp

(C 6-11)

1.43

Later, tests by CEA-EDF indicated that a realistic residual velocity is given by

using a factor of 1.29 instead of 1.43 in Equation C 6-11. Thus, for reinforced

concrete with a density of 156 lb/ft3 (2500 Kg/m3), the perforation thickness (tp) is

given by:

(V)

0.765 (fc)

(C 6-12)

where:

f/c

ultimate compressive strength of concrete (lb/in2);

missile nominal diameter (in.);

missile weight (lb);

missile impact velocity (ft/sec).

To prevent perforation, minimum concrete thickness, td, shall be

1.2 tp.

C-11