New Forming Processes for Sheet Metal with Large Plastic Deformation


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Due to the high effort involved, bifurcated constructions in mass market products made from sheet metal remained largely unused. Extruded profiles with cross-sections containing bifurcations show the possibility to increase the stiffness and allow modern lightweight design using load optimized structures as well as in box strap, sandwich and stringer constructions or different profiles. The two new forming processes linear flow splitting and linear bend splitting developed at the PtU enable the production of bifurcated profiles in integral style made of sheet metal without joining, lamination of material or heating of the semi-finished product. These forming processes use obtuse angled splitting rolls and supporting rolls to transform the sheet metal at ambient temperature. Whereas the linear flow splitting process increase the surface of the band edge and forms the band into two flanges. At linear bend splitting a bended sheet metal as semi finished product is used. Thereby bifurcations at nearly any place of a sheet metal can be produced. Both processes induce high hydrostatic compressive stresses in the local forming zone during the process which leads to an increased formability of the material and thereby to the realization of large strains. Parts produced are characterized by increased stiffness, high surface hardness and low surface roughness. Experimental investigations have shown an increasing of the band edge surface at maximum splitting depth up to 1800%. By a following forming process new multi-chambered structures and integral stringer construction can be realized with thin walled cross-sections from steel of higher strength.



Main Theme:

Edited by:

F. Micari, M. Geiger, J. Duflou, B. Shirvani, R. Clarke, R. Di Lorenzo and L. Fratini




P. Groche et al., "New Forming Processes for Sheet Metal with Large Plastic Deformation", Key Engineering Materials, Vol. 344, pp. 251-258, 2007

Online since:

July 2007




[1] Groche, P.; Vucic, D.: Stiffness-optimized lightweight design by new forming processes for sheet metal. Frankfurt: MAT INFO Werkstoff-Informationsgesellschaft mbh; 05/(2004).

[2] Kleiner, M.; Geiger, M.; Klaus, A.: Manufacturing of Lightweight Components by Metal Forming, Annals of the CIRP Vol. 52/2/2003, (2003).


[3] Groche, P.; Vucic, D., Jöckel, M.: Herstellung einteilig verzweigter Blechstrukturen, In: wt Werkstattstechnik, VDI Springer, 2005, p.753.

[4] Jöckel, M.: Grundlagen des Spaltprofilierens von Blechplatinen; Dissertation am Institut für Produktionstechnik und Umformmaschinen der TU Darmstadt, Shaker Verlag, Aachen2005, ISBN: 3-8322-4218-X.

[5] Groche, P.; Vucic, D.: Multi-chambered Profiles Made from High-Strength Sheets; In: Production Engineering, Annals of the WGP, Vol. XIII/1, Hannover, 04/2006, pp.67-70, ISBN 3-9807670-8-6.