Lehrstuhl für Fertigungstechnologie, Universität Erlangen-Nürnberg

Improved characterization of failure behaviours of sheet metals based on pattern recognition methods

Project Status: finished


The aim of the research project is an objective classification of failure behaviour of sheet metals during Nakajima tests with the aid of pattern recognition methods. In this project, pattern recognition methods are used to determine the failure stages during a sheet metal forming process. Prerequisite for the method development is a comprehensive metallographic analysis, the description of the material physical characteristics and the classification of different failure stages, depending on the material as well as on the stress and strain state.

Pattern recognition methods will be developed in order to detect and classify the failure stages based on surface characteristics. In contrast to the previous approaches, the pattern recognition method will fulfil the criteria of objectivity and user-independence.

The project is in cooperation with the Department of Pattern Recognition in Erlangen.



Research Groups



    • Affronti, E.; Jaremenko, C.; Merklein, M.; Maier, A.:
      Analysis of Forming Limits in Sheet Metal Forming with Pattern Recognition Methods. Part 1: Characterization of Onset of Necking and Expert Evaluation.
      Materials 11(2018)9, 1495, published online

    • Affronti, E.; Weidinger, M.; Merklein, M.:
      Metallographic analysis of failure mechanisms during Nakajima tests for the evaluation of forming limits on a dual-phase steel.
      IOP Conference Series: Materials Science and Engineering 418(2018)012047, published online

    • Jaremenko, C.; Affronti, E.; Maier, A.; Merklein, M.:
      Analysis of Forming Limits in Sheet Metal Forming with Pattern Recognition Methods. Part 2: Unsupervised Methodology and Application.
      Materials 11(2018)10, 1892, published online


    • Affronti, E.; Merklein, M.:
      Metallographic Analysis of Nakajima Tests for the Evaluation of the Failure Developments.
      In: Livan Fratini (Edtr.): Procedia Engineering, 2017, pp. 83-88

    • Jaremenko, C.; Huang, X.; Affronti, E.; Merklein, M.; Maier, A.:
      Sheet metal forming limits as classification problem.
      In: (Edtr.): Proceedings of the 15th IAPR International Conference on Machine Vision Applications (Machine Vision Applications), Nagoya University, Nagoya, Japan, 2017, pp. 100-103

    Letztes Update: 25.07.2018