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(3) [lambda]y = y/W1/3 = 10/1,0001/3 = 1 ft/lb1/3
(4) For [lambda]y = 1.0, go to Figure 20.
At [lambda]x = 6, [lambda]d = 2.5, read an
overpressure of 0.5 psi
P = 0.5 psi +/ 0.15 psi
d.
Primary Fragments from Cased Cylindrical Charges.
Problem:
Determine the striking velocity of primary fragments, the
weight of the largest fragment corresponding to a prescribed
confidence level and the number of fragments having a weight
greater than a specified amount.
Given:
(1) Type and density of explosive
(2) Type and density of casing material
(3) Casing thickness, tc
(4) Inside diameter of casing, di
(5) Length of charge
(6) Design Confidence Level, CL
(7) Distance traveled by fragment, Rf
(8) Critical fragment weight
Solution:
(1) Calculate the total weight of the explosive, W, and the
total weight of the cylindrical portion of the metal
casing, Wc. Increase the explosive weight by 20 percent
(paragraph 2.b, this section).
(2) Determine the Gurney constant, [(2E')1/2], for the
particular explosive from Table 3. For the case of a
cylinder uniformly filled with explosive, calculate the
initial velocity, Vo, of the primary fragments from
Equation (21):
Vo = (2E')1/2[(W/Wc)/(1 + 0.5W/Wc)]1/2
For other container and explosive crosssections, see
Table 2.
(3) Determine the value of the constant, B, for the explosive
from Table 3. With this value and the values of the
casing diameter, tc, and the average inside diameter,
di, calculate the fragment distribution parameter, MA,
from Equation (23b):
2.0862


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