A series of pedestrian sideswipe impacts were computationally reconstructed; a fast-walking pedestrian was collided laterally with the side of a moving vehicle at 25 km/h or 40 km/h, which resulted in rotating the pedestrian's body axially. Potential severity of traumatic brain injury (TBI) was assessed using linear and rotational acceleration pulses applied to the head and by measuring intracranial brain tissue deformation. We found that TBI risk due to secondary head strike with the ground can be much greater than that due to primary head strike with the vehicle. Further, an “effective” head mass, meff, was computed based upon the impulse and vertical velocity change involved in the secondary head strike, which mostly exceeded the mass of the adult head-form impactor (4.5 kg) commonly used for a current regulatory impact test for pedestrian safety assessment. Our results demonstrated that a sport utility vehicle (SUV) is more aggressive than a sedan due to the differences in frontal shape. Additionally, it was highlighted that a striking vehicle velocity should be lower than 25 km/h at the moment of impact to exclude the potential risk of sustaining TBI, which would be mitigated by actively controlling meff, because meff is closely associated with a rotational acceleration pulse applied to the head involved in the final event of ground contact.

References

References
1.
Peng
,
Y.
,
Chen
,
Y.
,
Yang
,
J.
,
Otte
,
D.
, and
Willinger
,
R.
,
2012
, “
A Study of Pedestrian and Bicyclist Exposure to Head Injury in Passenger Car Collisions Based on Accident Data and Simulations
,”
Saf. Sci.
,
50
(
9
), pp.
1749
1759
.
2.
ITARDA,
2010
, “Car-to-Pedestrian Accidents,” Institute for Traffic Accident Research and Data Analysis, Tokyo, Japan, ITARDA Information No. 83 (in Japanese).
3.
Tamura
,
A.
,
Koide
,
T.
, and
Yang
,
K. H.
,
2015
, “
Effects of Ground Impact on Traumatic Brain Injury in a Fender Vault Pedestrian Crash
,”
Int. J. Veh. Saf.
,
8
(
1
), pp.
85
100
.
4.
Tamura
,
A.
,
Koide
,
T.
, and
Yang
,
K. H.
,
2016
, “
Effects of Translational and Rotational Accelerations on Traumatic Brain Injury in a Sport Utility Vehicle-to-Pedestrian Crash
,”
Int. J. Veh. Des.
,
72
(
3
), pp.
208
229
.
5.
Hamdane
,
H.
,
Serre
,
T.
,
Masson
,
C.
, and
Anderson
,
R.
,
2015
, “
Issues and Challenges for Pedestrian Active Safety Systems Based on Real World Accidents
,”
Accid. Anal. Prev.
,
82
, pp.
53
60
.
6.
Crocetta
,
G.
,
Piantini
,
S.
,
Pierini
,
M.
, and
Simms
,
C.
,
2015
, “
The Influence of Vehicle Front-End Design on Pedestrian Ground Impact
,”
Accid. Anal. Prev.
,
79
, pp.
56
69
.
7.
Simms
,
C.
, and
Wood
,
D.
,
2009
,
Pedestrian and Cyclist Impact: A Biomechanical Perspective
,
Springer, Dordrecht
,
The Netherlands
.
8.
Bandak
,
F.
, and
Eppinger
,
R.
,
1994
, “A Three-Dimensional Finite Element Analysis of the Human Brain Under Combined Rotational and Translational Accelerations,”
SAE
Paper No. 942215.
9.
Addison
,
B.
, and
Lieberman
,
D.
,
2015
, “
Tradeoffs Between Impact Loading Rate, Vertical Impulse and Effective Mass for Walkers and Heel Strike Runners Wearing Footwear of Varying Stiffness
,”
J. Biomech.
,
48
(
7
), pp.
1318
1324
.
10.
Hutchinson
,
J.
,
Kaiser
,
M.
, and
Lankarani
,
H.
,
1998
, “
The Head Injury Criterion (HIC) Functional
,”
Appl. Math. Comput.
, 96(
1
), pp.
1
16
.
11.
Ommaya
,
A.
,
Goldsmith
,
W.
, and
Thibault
,
L.
,
2002
, “
Biomechanics and Neuropathology of Adult and Pediatric Head Injury
,”
Br. J. Neurosurg.
,
16
(
3
), pp.
220
242
.
12.
Schmitt
,
K.-U.
,
Niederer
,
P. F.
,
Muser
,
M. H.
, and
Waltz
,
F.
,
2007
,
Trauma Biomechanics: Accidental Injury in Traffic and Sports
,
2nd ed.
,
Springer-Verlag
,
Berlin
.
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