End flare of linear flow split profiles

  • M. MonekeEmail author
  • P. Mahajan
  • P. Groche
Original Research


One approach to design load optimized structures is the use of bifurcations. Linear flow splitting is a continuous sheet-bulk metal forming process, whereby bifurcated profiles are manufactured without joining or external heat supply. By roll forming linear flow split profiles, a wide spectrum of profile geometries can be realized, e.g. multi-chamber-profiles. Those profiles often require high dimensional accuracy to ensure their functionality. During roll forming, process related residual stresses are induced, which are released when the profiles are cut to length. Thereby increased deformation at the profile ends occurs, also known as end flare. End flare of bifurcated profiles has not been investigated so far. The aim of this research is to investigate end flare after roll forming of linear flow split profiles. Therefore, end flare after roll forming of a conventional sheet metal and a linear flow split profile is compared. The effect of residual stresses induced by linear flow splitting as well as the effect of additional geometrical stiffness due to the bifurcations on the development of end flare are examined. It is found that the residual stresses induced by linear flow splitting have no significant effect on end flare. However, the geometrical bifurcation affects the roll forming process, leading to higher residual stresses in the flange, which significantly affect the magnitude and the direction of end flare.


Linear flow splitting Roll forming Finite element analysis Residual stresses End flare 



The investigations presented in this paper are supported by the German Research Foundation (DFG). The authors would like to thank DFG for funding the Collaborative Research Centre 666 “Integral sheet metal design with higher order bifurcations – Development, Production, Evaluation”.


This study was funded by the German Research Foundation (DFG) as part of Collaborative Research Center 666 (CRC 666).

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.


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Copyright information

© Springer-Verlag France SAS, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Technische Universität DarmstadtInstitute for Production Engineering and Forming MachinesDarmstadtGermany

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