SAE Update - September 2022 - 24

TECH FOCUS:
VEHiClE iNTEriOrS
rear-seat safety gets
the attention it deserves
Experimentation and regulations involving vehicle
occupant protection typically focus on the front seats,
which are where 92% of motor vehicle fatalities occur,
according to a team of researchers at Virginia
Polytechnic Institute and State University.
And so it makes sense that the safety of the front
seats has improved greatly over the years, usually
outperforming the rear seats.
The rise of ridesharing and automated driving
systems (ADS) is expected to increase rear-seat
occupancy by adults, which may increase occupant
injury risks. The main objective of a recent study by
The Virginia Poly team, described here in the SAE
International Journal of Transportation Safety, was to
develop an efficient numerical methodology that
could be used to evaluate the safety performance of
current vehicle rear seats.
The rear-seat models of eight vehicles were
developed based on their geometry reconstructed
from three-dimensional (3D) digitizer scans. Seat
foam material properties were taken from tests of
each seat. Validated finite element (FE) models of
THOR-50M and Hybrid III male 50th percentile
anthropomorphic test devices (ATDs) were positioned
and settled in each seat model. The frontal New Car
Assessment Program (NCAP) crash pulses were
applied to each vehicle. Injury likelihood was assessed
by a summary of the AIS3+ risk curves for the head,
neck, and chest. Then, six rear seats were selected
and tested on a sled. The restraint system model and
dummy pre-crash position were slightly adjusted
based on the test data.
24
September 2022
The accuracy of the numerical
approach to investigate the
safety of rear seats was
evaluated by the researchers
under varying scaled NCAP
pulses against sled test data.
Overall, the seat models with
advanced restraints (e.g.,
pretensioners, load limiters)
and/or a steep seat pan angle
had the lowest injury risk. The
results of the simulations with
varying impact pulses showed
reasonable agreement with test
data that validate the numerical
UPDATE

https://www.sae.org/publications/collections/content/E-JOURNAL-09/ https://saemobilus.sae.org/content/09-10-02-0014/ https://www.sae.org/publications/collections/content/E-JOURNAL-09/ https://www.sae.org/publications/collections/content/E-JOURNAL-09/

SAE Update - September 2022

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