A scientific benchmark for elasto-plastic constitutive modeling - Part II: blind predictions, calibration strategies, and benchmark results

International Journal of Material Forming, vol. 19

Abstract

Abstract This paper presents the second part of the NUMISHEET 2025 scientific benchmark on elasto-plastic constitutive modeling. The study builds on the experimental dataset and benchmark problem definition introduced in Part I. It evaluates 19 blind prediction results submitted by 17 international teams from academia and industry. The benchmark task included calibrating constitutive models for the dual-phase steel DP800HHE, exclusively based on Part I data. The calibrated constitutive models were used to simulate the validation experiment MUC-Test, without prior access to the experimental validation results. The submitted solutions span a broad spectrum of modeling strategies, ranging from different phenomenological hardening models and yield locus formulations to crystal plasticity approaches. A systematic comparison with experimental ground truth data (comprising punch force-displacement curves and local strain distributions) was conducted using normalized error metrics. The results of this study reveal the characteristic strengths and limitations of different modeling approaches. They also highlight the role of anisotropy and hardening law selection. Furthermore, they demonstrate the sensitivity of predictions to calibration strategies. Providing an open dataset, a transparent evaluation methodology, and a comprehensive discussion of outcomes signifies an advancement in reproducibility and objectivity in constitutive modeling. This benchmark serves as a basis for further validation, comparison, and development of constitutive models. Dataset https://zenodo.org/records/18431261

Authors 13

1. Lorenz MAIER corresponding

   Technical University of Munich

   Affiliation as printed

   Chair of Metal Forming and Casting, Technical University of Munich, Garching near Munich, Germany

2. Erik Walz corresponding

   Technical University of Munich

   Affiliation as printed

   Research Neutron Source Heinz Maier-Leibnitz, Technical University of Munich, Garching near Munich, Germany

3. M. Hofmann corresponding

   Technical University of Munich

   Affiliation as printed

   Research Neutron Source Heinz Maier-Leibnitz, Technical University of Munich, Garching near Munich, Germany

4. Joana Rebelo-Kornmeier

   Technical University of Munich

   Affiliation as printed

   Research Neutron Source Heinz Maier-Leibnitz , Technical University of Munich , Lichtenbergstreet 1 , Garching near Munich 85748 , Germany

5. Rongfei Juan corresponding

   Aalto University

   Affiliation as printed

   Materials to Products, Aalto University, Espoo, Finland

6. Junhe Lian corresponding Aachen Chair of Forming Technologies Institute of Metal Forming

   RWTH Aachen University

   Affiliation as printed

   Chair of Forming Technologies and Institute of Metal Forming, RWTH Aachen University, Aachen, Germany

7. Youngung Jeong corresponding

   Changwon National University

   Affiliation as printed

   Department of Materials Science and Metallurgy, Changwon National University, Changwon-si, South Korea

8. Bohye Jeon corresponding

   Changwon National University

   Affiliation as printed

   Department of Materials Convergence System Engineering, Changwon National University, Changwon-si, South Korea

9. Martin Milch corresponding
   Affiliation as printed

   AutoForm Engineering Deutschland GmbH, Dortmund, Germany

10. Alper Güner corresponding
    Affiliation as printed

    AutoForm Engineering Deutschland GmbH, Dortmund, Germany

11. Emad Maawad corresponding

    Helmholtz-Zentrum Hereon

    Affiliation as printed

    Institute of Materials Physics, Helmholtz-Zentrum Hereon, Geesthacht, Germany

12. Wolfram Volk corresponding

    Technical University of Munich

    Affiliation as printed

    Chair of Metal Forming and Casting, Technical University of Munich, Garching near Munich, Germany

13. Christoph Hartmann corresponding

    Technical University of Munich

    Affiliation as printed

    Chair of Metal Forming and Casting, Technical University of Munich, Garching near Munich, Germany