
 DOESTD301496
TABLE I.* Empirical formulas for local response evaluation of reinforced
concrete targets (see Note 1).
RIGID
SOFT
(NONDEFORMABLE)
(DEFORMABLE)
DAMAGE MODE
MISSILE
MISSILE
(See Note 2)
Penetration (x)3
Modified NDRC
50% of Rigid
Scabbing (ts)4
 Modified NDRC
60% of Rigid
 Bechtel
or
 Chang7
 Stone &
 CRIEPI
Webster
Perforation (tp)5
 Modified NDRC
70% of Rigid
 CEA  EDF
 Degen
 Chang7
 CRIEPI
Punching Shear6
 ACI7
 Long
NOTES:
1.
For a typical example using these empirical formulas and a discussion of their relative merits, please refer to
Section 3 of the technical support document (Reference 1) and Table A1 therein. These formulas are not
applicable to unreinforced concrete or masonry structures.
2.
The reduction factors for deformable missiles acknowledge the fact that they produce relatively less local
damage, and the impact forces do not exceed the crushing strength of these missiles. They are based on
recent aircraft engine missile tests and comparison of various empirical formulas and their agreement with the
actual test results, as reported by Sugano (Reference 5).
3.
Penetration (x) is computed to determine t s and tp (Modified NDRC and Degen formulas only).
4.
To prevent scabbing, minimum required thickness t
should be > 1.1 ts.
d
5.
To prevent perforation, minimum required thickness t
should be > 1.2 tp.
d
6.
Punching shear considerations for small nondeformable missiles are implicit in the formulas for penetration and
perforation.
7.
Recommended formula (see Section 6.3.2.1). References for all other formulas are given in Appendix C.
*All of the formulas presented in this table are based on data for lightly reinforced (0.3 percent  1.5 percent each way)
concrete targets. Application to heavily reinforced targets would give a conservative estimate of local response.
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