Shown also in Figs. A.3 and A.5 are the calculated displacements performed for Shot 9, UPSHOT-KNOTHOLE. This shot was a high air burst
weapon and the calculated displacements were the values resulting from
the horizontal comporent of dynamic pressure. The dynamic pressures
(eq icheel were obtained from the usual Rankine-Hugoniot relation,
Eq. Al).
P, = 2.5 (P,)
2
(A.1)
o * Ps
with P. = ls7 psi.
The horizontal lines shown in Figs. A.3 turough A.6 depict the
damage that may be expected for the calculated displacements. The
correlation of displacement with damage to 1/4-ton trucks was obtained from a statistical analysis of previous data. The treatment of the
data involved the analysis of “sensitivity data" (see Reference 6).
This correlation is shown in Fig. A.7, which gives the probability of
damage to 1/4-ton trucks versus displacement and is for side-on
orientation only. Since there was no overlap of data in the region
of moderate and severe damage, neither the mean value » nor the standard
deviation o could be calculated for the probability of severe damage.
The mean value of displacement for50 percent probability of light
damage is p = 27.1 feet and standard deviation is o = 3.66 feet.
The
interval of displacement for 50 percent probability of severe damage
is 40¢€u<'/2 feet.
The values ofthe horizontal lines shown in the
figures mentioned above are 27.1“féet fer 50 percent probability of
light damage and 72 feet, above which“dg severe damage.
A study of the curves indicates” that for drag targets that are
damaged when moved, such as vehicles,.anadditional increase in lethal
area may occur resulting from the longer duration of the large yields.
The longer duration lowers the dynamic pressure for specific type
damage and thus they9gius of damage extenda beyond the usual scaling
value, i.e., using
for scaling the distance. from ground zero fer
a given value of dynamic pressure.
To determine the exponent of the
yield, W, for scaling the lethal radius for specific damage, a curve
was drawn (see Fig. A.8) showing the distance from ground zero for
which a given displacement can be expected from different size weapons
burst at surface level. The values of displacement selected from Figs.
A.3 and A.& were for side-on orientation and for pw = 0145, sliding
coefficient of friction. The actual displacements of-jeeps-in Shot 9,
UPSHOT-KNOTHOLE, for side-on orientation within the Mach region were
scattered about the displacement curve calculated for a sliding coefficient of friction of np = 0.5. Additional calculations: for displacement were performed for yields other than those mentioned to
cover the range of yields from 0.1 KT up to 10 MP.
The slope of the
curves varies from a minimm cf 0.40 up to a maximum of 0.5 which .—
suggests that by average value for scaling the yleld, W, for damage
should be as W
28