french institute of science and technology for transport ... - Ifsttar

Research orientation 3_Accident analyses, biomechanics, health
Finite element modelling
Pregnant women and children first
The LBA has been investigating the protection of
pregnant women and children in the event of a car crash
for almost 8 years, in close collaboration with the Nice
and Marseille welfare services.
The defence of the doctoral theses by François
Coulangeat (1) and Jérémie Pérès (2) had a considerable impact
on this topic in 2011. Both studies developed detailed finite
element models for assessing the vulnerability of these groups
of users and proposing new protection devices.
With regard to pregnant women, the recent advances have
identified new injury criteria that are backed up by the available
epidemiological data. In particular, these criteria are based on
fluid-structure coupling that provides accurate modelling of the
interactions between the uterus, the placenta and the foetus
within the amniotic fluid.
By simulating a variety of impacts, the influence of the
adjustments that are available in the passenger compartment
(position of the seat and steering wheel) on the unborn child’s
fatality risk was assessed and should provide the basis for
recommendations that are based on more objective observations.
(1) A finite element numerical model of a child.
(2) Injury mechanisms in pregnant women and their foetus during a road
traffic accident.
Numerical models dealing with the protection of pregnant
women and children.
This model means we can now envisage optimizing restraint
systems. The development of a comprehensive bio-faithful
numerical model of a six year-old child, the first of its type, was
finalized by the reconstruction of a real crash, in partnership
with the Accident Mechanisms Unit.
@ CONTACT
michel.behr@ifsttar.fr
Modelling the abdomen
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The first phase of the projects conducted by the Global
Human Body Modelling Consortium (GHBMC) is drawing
to a close. Its goal was to create the first complete model
of a human being that was as bio-faithful as possible.
This ambitious programme was launched in 2008
with funding from a global consortium consisting of 8 vehicle
manufacturers, one subcontractor and NHTSA (the American
National Highway Traffic Safety Agency). The GHBMC has entrusted
the various topics to six centres of academic expertise:
Wake Forest University for geometry and assembly, Wayne
State University for the head, Waterloo University for the neck,
University of Virginia for the thorax, University of Virginia with
the University of Alabama in Birmingham for the lower limb
and IFSTTAR with Virginia Tech for the abdomen (LBMC
modelled the abdomen, while Virginia Tech carried out the
experimental work).
LBMC’s part of the work follows on from a doctoral
thesis on abdominal modelling (with Lab
PSARenault) and another on the characterization
of liver tissue (with the INSA in Lyon). The
abdomen develop by LBMC was validated under
12 impact configurations and the first injury
criteria were proposed for the liver and
spleen. Validation work will continue using
data on the kinematics of internal
organs obtained by Virginia Tech.
The model has been tested
in full or in part under more
than 60 impact conditions,
and injury criteria have been
proposed for most anatomical
regions.
This model is intended to become the reference
human model in the industrial and academic sectors for improving
safety. Research is due to continue, amongst other
things to create models that represent other groups.
@ CONTACT
philippe.beillas@ifsttar.fr
Lhe GHBMC 50 th percentile model for a man (Phase 1)
contains approximately 2 million elements. It has been
tested under more than 60 impact conditions. The LBMC
was responsible for modelling the abdomen.
ANNUAL REPORT 2011 ifsttar.fr