Abstract:
A study has been conducted into the development of Impact Management Seating
Systems (IMSS's) for improved occupant protection during rear impacts. The seating
systems incorporate methodologies that enable the supporting surfaces to pivot in a
controlled manner during the onset of the impact event. This enables the seated
occupant to penetrate an outer perimeter frame, whilst simultaneously having the
effective ride height lowered. This response is typically referred to as the 'Catchers-
Mitt' principal, and provides the occupant with localised 'ride-down', and optimum
positioning with respects to the head restraint.
Such seating systems can compliment the 'ride-down' characteristics provided by
vehicle' crush-zones', or in the case of small and Low Mass Vehicle (LMV) designs,
which can suffer from inefficient 'crush-zones' due to geometric restrictions, can be the
primary source of impact management.
Pivotal systems typically rely on the use of yielding elements to initiate the desired
deployment. However, these are inherently restrictive in their ability to adapt to
changes in occupant mass and impact magnitude. Solutions are presented to address
this and other limitations. Such solutions include the use automatic inflation/deflation
technologies, and Siding Plate Anchorage Systems that provide the seated occupant
with a supportive surface during deployment of the pivotal mechanisms, and the
reposition of the restraint system to address issues with 'rebound-reactions' and/or
multiple impact events.
LS-DYNA simulations determined the effectiveness of the developed seating systems in
controlling a dummy response. Significant reductions in head acceleration and the
movements thought responsible for whiplash and Whiplash Associated Disorders were
achieved. The realisation of the seating systems is examined. Consideration is given to
issues associated with seat mass, to enable the systems to be installed within Low Mass
Vehicle (LMV) designs without compromising environmental gains.