Two manufacturers, Denton ATD and FTSS, currently produce the
Hybrid III 5th percentile female dummy. In response to concerns
raised by industry that differences in the anthropometry of the
molded breasts between the two manufacturers may influence chest
responses, Transport Canada conducted a comparative testing
program. Thorax biofidelity tests were conducted to compare
force-deflection characteristics; full-frontal, rigid-barrier tests
were conducted at 40, 48 and 56 km/h to compare chest responses,
and out-of-position chest on module static airbag deployment tests
were conducted to compare peak chest deflections of the Denton and
FTSS dummy jackets and of a prototype jacket without breasts.
Differences in force-deflection characteristics were observed
during biofidelity pendulum impacts of the two dummies, with much
of the differences attributed to the different chest jackets.
Differences of up to 11 mm in the peak sternum deflection and of
the order of 15 g for the 3-ms chest acceleration clips were noted
in rigid-barrier vehicle tests. In the out-of-position airbag
deployment tests, differences in the magnitude of peak chest
deflections were observed. The prototype chest jacket without
breasts was found to improve repeatability in the belted crash
tests and in out-of-position airbag testing.
Though neither the Denton nor the FTSS chest jackets fully meet
the original design intent of the Hybrid III 5th percentile dummy,
the Denton dummy more closely met the drawing specifications and
had less manufacturing variability. The results demonstrate the
importance of detailed chest flesh assembly specifications, provide
evidence that a fully molded jacket design would eliminate
manufacturing variability and suggest that removal of the breasts
may further improve test repeatability.