MIL-PRF-9884F
4.3.1 Dynamic crushing stress and rebound energy verification. The sample unit shall consist
of two specimens, each 16 inches by 18 inches, cut from each of five pads selected at random
from the lot. One specimen shall be cut from one end of the pad, and the second from the
opposite end. The two specimens from each pad shall be bonded or taped to each other to form a
6-inch thick sample unit. Each sample unit shall be tested for dynamic crushing stress and
rebound energy to a 70% minimum strain. Each sample unit shall be impacted by a mass with a
contact area of at least 16 inches by 18 inches at a velocity of 28 to 30 feet per second that will
crush to at least 70% of the sample thickness. Verify that the crushing stress for each sample unit
is 6300 + 900 pounds per square foot to 70% minimum strain and the stress-strain curve shall be
essentially rectangular for a minimum of 0 to 70% strain. The rebound energy shall not exceed
8% of the absorbed energy to a 70% minimum strain. A retest is permitted if one of the five
sample units tested fail to meet the requirements. The number of sample units for a retest shall be
eight. Verify that seven of the eight retest samples meet the requirements specified above.
4.3.2 Static load verification. A specimen 12 inches square, shall be cut from a pad selected
at random from the lot. A 4000-pound minimum static load shall be applied uniformly on the top
surface of the specimen and allowed to sit for a minimum of 5 minutes. Verify that the specimen
does not deflect greater than 1/16 inch.
4.3.3 Cutability verification. The specimen shall be one pad selected at random. A pad used
for cutting the specimens in 4.3.1 may be used. Verify cutability using a parachute rigger's knife
(2-1/2 inch minimum blade). The pad shall be capable of being cut by hand, in two separate
pieces, across the width with two strokes of the knife. If necessary, after the first cut, cut across
the pad again on the same side or turn the pad over and cut in line with the first cut. The pad
may be folded into two pieces by bending along the first cut line and cutting along the fold line.
4.4 Interface and interoperability verification. All interface and interoperability
requirements shall be verified as follows:
4.4.1 Verify, by measuring that the dimensions of the energy dissipator pad are 36 inches by
96 inches + 1/2 inch, and the thickness is 3 inches + 1/16 inch. These dimensions are necessary to
be compatible with current field manuals and methods of storing.
4.4.2 Surface bonding verification. The surfaces of the energy dissipator pad shall be capable
of being bonded to each other and to pieces of wood using the adhesive paste cited in current field
manuals (see 6.6). Verify that there is no shifting or movement of the pads after adhesive has
dried.
4.5 Support or ownership verification. All support or ownership requirements shall be
verified as follows:
4.5.1 Weight examination. Verify, by weighing, that one cubic foot of the energy dissipator
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