Advanced Materials Research Vols. 6-8 (2005) pp.
13-18
online at http://www.scientific.net
© (2005) Trans Tech Publications, Switzerland
FE Simulation of Sheet Metal Forming – State of the Art
in Automotive Industry
H. J. Haeppa and M. Rohlederb
DaimlerChrysler AG, Production Planning Mercedes-Benz Passenger Cars, HPC B510,
71059 Sindelfingen, Germany
Copy,Edit and Printing deactivated. Original document has 6 pages
a
hans-josef.haepp@daimlerchrysler.com, bmartin.rohleder@daimlerchrysler.com
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Keywords: sheet metal forming, die development process, springback compensation
Abstract. Nowadays feasibility studies using finite element analysis are performed in very early
design phases of sheet metal parts forming. Further, simulation technology is used to optimize the
first forming stage. Because of the ever intensifying international competition and the increased use
of high-strength steels and aluminum alloys, the absorption of springback deviations is a great chal-
lenge, especially in the automotive industry. The application of numerical computation to predict
springback deviations and to create compensated die designs in early design phases of sheet metal
parts forming becomes essential. At DaimlerChrysler the numerically based compensation of
springback deviations during the die development process of complex car parts is achieved. How-
ever, developments to optimize and compensate dies automatically or to predict form deviations on
assemblies are still necessary.
Introduction
The ever intensifying international competition in the automotive industry leads to shortened prod-
uct cycle times and faster speed to market. A further trend is the continuous increase in the vehicle
models and in the complexity of parts, especially outer panels. Vehicles of less fuel consumption
and weight will be essential in the future. Thus, the average content of high strength and dual-phase
steels as well as aluminum alloys in automobiles will increase further.
In the automotive industry regarding costs, time and quality, more and more demands are placed
on forming technologies. Sheet metal forming technologies are often used for the production of car
outer panels. Thus, the design of the sheet metal forming tools and their capability to reliably manu-
facture the desired geometry becomes a central meaning in the automotive industry [1]. The goal is,
that the designed tools can be used directly for the mass production without any trial and error proc-
ess at the beginning. Additionally, the shape of the manufactured parts should correspond exactly to
the design intended geometry.
State of the Art of Sheet Metal Forming Simulation
Today numerical feasibility studies of the first forming operation are already performed in early
design phases of the sheet metal forming parts, the finite element analysis is mainly used. Fig. 1
illustrates the predictable variables offered by sheet forming simulation. Failures such as cracks and
wrinkles, the material flow as well as thickness and strain distribution can be very successfully de-
termined in advance. This has permitted an enormous time and cost reduction in the die design
process of the first forming stage. An experienced user will also be able to reliably predict the draw-
in, the initial blank outline, springback deviations and forces, while the determination of surface
defects and wrinkling under contact conditions give rise to some difficulty [2].
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