Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Identification and modeling of material characteristics for Finite-Element-Analysis of sheet metal forming processes - phase II

Project Status: finished


TP2: Characterization and evaluation of yield loci and subsequent yield loci under observation of the isotropic-kinematic hardening (finished)


TP6: Verification and validation of subsequent yield loci by means of practical deep drawing parts

In the course of an advanced claim for reduced consumption of energy and resources a consistent improvement of manufacturing processes, the analysis of new materials, as well as the application of numerical simulation processes are essential. Straight under the aspect of lightweight potential the adoption of new materials plays a decisive role, especially in the automotive and aviation industry. In order to fulfill this demand, it takes an accurate description of the material behavior during the forming process. Nowadays finite element analysis will be applied to predict the springback behavior in sheet metal forming. The target of this numerical description of the forming process is a repeatable forecast of the material behavior for the real molding process. The quality of the results of these numerical simulations for the most part depends on the input parameters. Thereby a pure isotropic hardening of the material is assumed as a simplistic representation. Especially at large deformations a directional and strain rate dependent hardening behavior can be observed. This kinematical component of the hardening is crucial for an exact projection of the real process in the simulation model. By disregarding this effect significant failure in the calculated stress state can cause a distortion of the springback behavior.

The superior goal of this fundamental research project, which is to be executed by scientists on academical and industrial research, is the determination and description of the material behavior, the identification of the required theoretical models, as well as the contained parameters, to enhance the existing prospects of process analysis and planning methods with the help of finite element analysis (FEA). For the attainment of the ambition this project builds on the fundamental investigations of the first project phase. The focus of this second phase is on the description of the isotropic-kinematic hardening behavior, especially on the characterization of the Bauschingereffect. The qualification of new test preparations for the investigation of extended material parameter serves as base for the development of schematic evaluation strategies for the identification of material models and parameters, as well as the associated theoretical bases. The core of the intention is a significant increase of the result quality of complex forming processes via finite element method (FEM) by means of improved modeling.






    • Suttner, S.; Merklein, M.:
      Influence of stress relaxation after uniaxial pre-straining on subsequent plastic yielding in the uniaxial tensile test of sheet metal.
      Key Eng. Mater. 639(2015), pp. 377-384

    • Suttner, S.; Merklein, M.:
      Characterization of the shear stress state under non-proportional strain paths realized by biaxial stretching in the Marciniak Test.
      Materials Today: Proceedings 2S(2015), pp. S98-S106


    • Yin, Q.; Zillmann, B.; Suttner, S.; Gerstein, G.; Biasutti, M.; Tekkaya, A. E.; Wagner, M. F.-X.; Merklein, M.; Schaper, M.; Halle, T.:
      An experimental and numerical investigation of different shear test configurations for sheet metal characterization.
      Int. J. Solids Struct. 51(2014)5, pp. 1066-1074

    • Merklein, M.; Suttner, S.; Schaub, A.:
      Experimental investigation of Ti-6Al-4V with a biaxial tensile test setup at elevated temperature.
      Key Eng. Mater. 622-623 (2014), pp. 273-278

    • Suttner, S.; Merklein, M.:
      Characterization of the Bauschinger effect and identification of the kinematic Chaboche model by tension-compression tests and cyclic shear tests.
      In: Sfar, H.; Maillard, A. (Edtrs.): Proc. International Deep Drawing Research Group Conf. IDDRG 2014, France, 2014, pp. 125-130

    • Merklein, M.; Suttner, S.; Brosius, A.:
      Characterisation of kinematic hardening and yield surface evolution from uniaxial to biaxial tension with continuous strain path change.
      CIRP Annals - Manufacturing Technology 63(2014)1, pp. 297-300

    • Suttner, S.; Rosenschon, M.; Merklein, M.:
      Methodik zur Parameteridentifikation des kinematischen Verfestigungsmodells nach Chaboche und Rousselier.
      In: W. Grellmann, H. Frenz (Edtr.): Tagungsband Werkstoffprüfung, DVM e.V., 2014, pp. 205-210


    • Merklein, M.; Suttner, S.:
      Evolution of yield loci for aluminum alloy AA6016 and deep drawing steel DC06 under the influence of non-linear strain paths.
      Key Eng. Mater. 549(2013), pp. 21-28

    • Suttner, S.; Kuppert, A.:
      Investigation of the beginning of plastic yielding and the hardening behaviour under biaxial tension.
      Adv. Mater. Res. 769(2013), pp. 197-204

    • Suttner, S.; Merklein, M.:
      Experimentelle Untersuchung des zweiachsigen Spannungszustands im Kreuzzugversuch zur Identifikation von Werkstoffmodellen für die Finite-Elemente Simulation.
      In: H.-J. Christ (Edtr.): Tagungsband Werkstoffprüfung, Stahleisen, 2013, pp. 59-64

    Letztes Update: 01.04.2016