An ideal injury criterion should be predictive of the risk of
injury across the range of loading conditions where it may be
applied. The injury risk curve associated with this criterion
should be applicable to all loading conditions. With respect to
side impact, the injury risk curve should apply to pure lateral or
oblique loading by rigid and padded walls, as well as airbags.
Trosseille et al., (2009) reported that the number of fractured
ribs was higher in pure lateral impact than in forward oblique
interaction with an airbag. A good dummy criterion should be able
to account for this difference. To evaluate various injury criteria
with the WorldSID 50th and ES-2re dummies, the dummies were exposed
to the same airbag loadings as the PMHS. The criteria measured in
the dummy tests were paired with the rib fractures from the PMHS
tests.
Regarding the effect of configuration, results of sled tests
with the 50th percentile WorldSID (Petitjean, 2009) and ES-2re
(Kuppa, 2003) have been paired with injuries found in the PMHS
tested in the same conditions. The relationships obtained were
compared with the relationships established in the same way for the
subjects loaded in the airbag tests.
Comparing the lateral and oblique lateral loading conditions,
both the WorldSID and the ES-2re exhibited differences in peak
lateral deflection of their ribs that were consistent with the
different number of rib fractures for PMHS subjected to these
loading conditions. For each dummy, the risk of rib fractures could
be assessed from one injury risk curve, regardless of the loading
angle. Furthermore, the same injury risk curve can be used to
assess the risk of rib fractures from sled tests and airbag
loading. However, because the WorldSID deflection measurements
differed in the rigid and padded sled tests, it is recommended that
the dummy's sensitivity to padding be further assessed prior to
adopting injury risk curves for WorldSID. Rib deflections of the
ES-2re were not sensitive to padding. Finally, VC should not be
considered as a valid criterion to assess the risk of rib
fractures.