Closures - Concepts made of steel
Automobiltechnische Zeitschrift, S. 562-569, Issue 6/2002
Dipl.-Ing. D. Schwarz, (ika, Aachen)
Dipl.-Ing. H. Bachem (ika, Aachen)
Dipl.-Ing. F. Friesen, (ika, Aachen)
Dipl.-Ing. Dipl. Wirt.-Ing. R. Wohlecker (fka, Aachen)
Dipl.-Ing. E. Hilfrich, TKS
Summary:
The pedestrian protection gains more and more importance in the frame
of the passive safety during the last years. The vehicle front takes
an important position in the context of the development of
pedestrian-friendly vehicles. Against this background a hood concept
which meets the requirements of the planned EU-regulations for
pedestrian protection has been developed by ika/fka in cooperation
with TKS.
The determination and the quantification of the most important
influencing parameters took place in parametric studies using modern
simulation methods. The fulfilment of the criteria of pedestrian
protection after EEVC-WG17 has been proven with numerical crash
simulations.
Head impact requirements can be met with a steel hood design. One
characteristic feature is the use of an outer panel from thin,
high-strength dual-phase steel, which has also been analysed with
regard to realisability, outer skin quality and bulging strength. The
new hood design shows a significant weight saving and high structural
stiffness. The hood structure has also been improved with regard to
economic aspects and series suitability and thus can be seen as a
competitive option for active systems and alternate materials.
The use of different optimisation methods with regard to light weight
construction has been shown at the example of a door concept. The
developed concept shows a weight reduction of about 20 %. In addition
to the weigth reduction, the stiffness values could have been raised.
By the use of a tailor welded blank, the number of parts can be
reduced by 2 parts. If there is a reduction of the high target
stiffness values possible, one can expect more weight reduction.
The described approach shows an efficient and targeted use of
different optimisation methods by the example of a steel light weight
construction concept of a driver's door. This approach is also in use
for other body and chassis parts at the ika/fka.
Two static load cases have been taken into account executing the
optimisations. Further static and dynamic load cases, like the door
intrusion after FMVSS-214, the consideration of functional and
acoustic properties are necessary for a more detailed workout of the
concept.
Bild 1: Optimierte Haube und Serienhaube im Vergleich
Bild 2: Originaltür und optimiertes Konzept einer Pkw-Leichtbautür in Stahlbau
