Development of a Component Head Injury Criteria (HIC ... - FAA

needed to be studied. For this, baseline FSSTs as well as component tests were conducted for
other seat setback distances using aluminum and Nomex panels and bulkheads. The tester
produced reasonably good performance in replicating the results of the FSSTs for the range of
seat setback distances tested, especially for small seat setback angles.
5.1 BASELINE FSSTs USING ALUMINUM PANELS.
A series of 12 FSSTs were conducted using a 0.063-inch-thick aluminum panel (Al 2024-T3) as
the bulkhead. The seat setback distance was varied from 28 to 35 in. to obtain head impact
angles from 27 to 61 degrees. The details of the tests and the results are discussed below.
A polyester lap belt was used for restraining the Hybrid II ATD. A load cell was attached to the
lap belt to determine the belt forces. Figures 10 and 11 show the FSST data plots obtained from
test 96288-16, the seat setback distance was 33.5 in. The results are listed in table 1.
Sled Acceleration Profile
Head C.G. Acceleration Time History
20
15
140
120
100
X - Component
Y - Component
Z-Component
Resultant
Sked Acceleration (g's)
10
5
0
-5
-10
Head C.G. Acceleration (g's)
80
60
40
20
0
-20
-40
-60
-80
-15
-100
-120
-20
3.1 3.15 3.2 3.25 3.3 3.35 3.4 3.45 3.5
Time (sec)
-140
3.25 3.3 3.35 3.4
Time (sec)
Figure 10. Acceleration Plots for FSST 96288-16
Head C.G.Resultant Acceleration Time History and HIC Calculation
140
HIC = 586
130
50
Resultant Head Velocity Time History
120
Head C.G.Acceleration (g's)
110
100
90
80
70
60
50
40
30
t1= 3.3191
t2 = 3.3572
Head Velocity (ft/sec)
40
30
20
10
20
10
0
3.25 3.3 3.35 3.4
Time (sec)
0
3.25 3.3 3.35 3.4 3.45 3.5 3.55
Time (sec)
Figure 11. Velocity Plots for FSST 96288-16
8