Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Determination of characteristic values of materials for sheet metal forming

Project Status: Active


Material testing is used to determine characteristic values which are needed as input parameters in finite element simulations. The material values can be determined with a multitude of tests, e.g. tension tests, compression tests, Nakajima tests, shear tests and bending tests as well as tests with load reversal.  Modern and complex yield criteria, for example the Barlat 2000 criterion, require the yield point under biaxial loading. The biaxial tensile test can therefore be used to achieve an additional data point in the first quadrant of the yield locus, which describes the point of plastic yielding under different loading conditions. At the LFT, a testing device was developed, in which the arms of a cruciform specimen can be subjected to a tensile load. Equibiaxial tension is achieved if the tensile forces at the end of the cruciform specimen are chosen equally. There are also other balances of forces possible. The strain distribution in the middle of the specimen is detected with an optical strain measurement system using a CCD camera.



Cruciform specimen and testing device for biaxial tensile test (developed at the LFT)

Research Groups



    • Merklein, M.; Tsoupis, I.; Gnibl, T.; Lechner, M.:
      Innovative manufacturing solutions for the efficient production of car bodies.
      In: Schmeing, K. (Edtr.): Forming in Car Body Engineering 2015, Vincentz Network GmbH & Co. KG, Hannover, 2015, pp. 67-86


    • Hotz, W.; Merklein, M.; Kuppert, A.; Friebe, H.; Klein, M.:
      Time dependent FLC determination - Comparison of different algorithms to detect the onset of unstable necking before fracture.
      Key Eng. Mater. 549(2013), pp. 397-404


    • Merklein, M.; Suttner, S.; Hofmann, M.; Kuppert, A.:
      Über die Blechprüfung von heute.
      In: M. Borsutzki, G. Moninger (Edtr.): Tagungsband Werkstoffprüfung, Stahleisen, 2012, pp. 1-6


    • Kuppert, A.; Merklein, M.:
      Enhanced Investigation of Flow and Necking Behavior of Sheet Metal within Layer Compression and Tensile Tests.
      In: DIMITROV, D. (Edtr.): Proc. of COMA 10, 2010, pp. 147-152

    • Merklein, M.; Kuppert, A.; Geiger, M.:
      Time dependent determination of forming limit diagrams.
      Annals of the CIRP 59-1(2010), pp. 295-298

    • Merklein, M.; Kuppert, A.; Mütze, S.; Geffert, A.:
      New Time Dependent Method for Determination of Forming Limit Curves Applied to SZBS800.
      In: Kolleck, R. (Edtr.): Proc. 50th Conference of IDDRG 2010, Verlag der Technischen Universität Graz, 2010, pp. 489-498


    • Merklein, M.; Kuppert, A.:
      A Method for the Layer Compression Test Considering the Anisotropic Material Behavior.
      In: (Edtr.): International Journal of Material Forming, Springer, 2009, pp. 483-486


    • Kuppert, A.; Merklein, M.:
      Ermittlung temperaturabhängiger Werkstoffkennwerte für die Auslegung von Halbwarm- und Warmumformprozessen.
      Metall - Magazin für die metallverarbeitende Wirtschaft 05.2008(2008)05, pp. 22-25

    • Merklein, M.; Kuppert, A.:
      Trends und Möglichkeiten der Prüftechnik zur Charakterisierung der Umformeigenschaften von Blechwerkstoffen.
      In: Zwick (Edtr.): testXpo - 17. Fachmesse für Prüftechnik, 2008, pp. 121-126


    • Merklein, M.; Hußnätter, W.; Staud, D.; Kuppert, A.:
      Charakterisierung der Umformeigenschaften von Blechwerkstoffen - Trends und Möglichkeiten der Prüftechnik.
      In: Pohl, M. (Edtr.): Tagungsband Werkstoffprüfung 2007, Stahleisen GmbH, 2007, pp. 201-210


    • Liebertz, H.; Duwel, A.; Illig, R.; Hotz, W.; Keller, S.; Koehler, A.; Kröff, A.; Merklein, M.; Rauer, J.; Staubwasser, L.; Steinbeck, G.; Vegter, H.:
      Guideline for the determination of forming limit curves.
      In: (Edtr.): Proceedings of IDDRG 2004, 2004, pp. 216-224

    Letztes Update: 03.07.2018