Benchmark Tests:
The NUMISHEET Benchmark Study is designed to evaluate the state of the art, as known and practiced by industry and academic research organizations, in their capability to predict the outcome of challenging problems in metal forming. NUMISHEET Benchmark Committees define several metal forming challenges approximately one year prior to the NUMISHEET Conference and ask the metal forming community to predict what happens and report the results by a deadline ahead of the conference. The Benchmark Committees then compile the submitted results and report them along with measurements from experiments, which are made public for the first time at the conference. Participants who do particularly well in predicting the results from the blind tests are recognized at the conference.
Scientific Benchmark – Material Under Control
The objective of the scientific benchmark of the upcoming NUMISHEET 2025 is to calibrate a material model for a dual phase steel, namely DP800. This benchmark will involve the use of experimental data from standard and advanced sheet metal tests, as well as data from microstructural analysis, such as electron backscatter diffraction and nano-indentation. The participants can decide, which set of experimental data they use to calibrate their chosen model.
After the material model has been calibrated, the simulation of a provided sheet metal forming test will be used to investigate the accuracy of the material model. The experimental setup and the tool geometry of the so-called MUC-Test has been specially developed for the validation of material models [EDER22]. The participants are going to use the MUC-Test to simulate three different specimen geometries in three rolling directions. Each of those nine simulations will be compared with the real experiments by the committee. Therefore, three cuts through the specimens at a specific punch stroke depth will be used for the major- and minor strain comparison between the simulation and the experiment. The force curves of the nine simulations will also be compared to the experimental results.
This comparison will provide a comprehensive understanding of how the complexity of the models affects the accuracy in sheet metal forming simulation. The user-dependent calibration can also be compared directly, if several participants use an identical material model. This knowledge can be used to improve the accuracy of simulations, optimize the forming processes, and ultimately improve part quality and reduce production costs.
References
Eder, M., Gruber, M. & Volk, W. Validation of material models for sheet metals using new test equipment. Int J Mater Form 15, 64 (2022). https://doi.org/10.1007/s12289-022-01710-7
Industrial Benchmark
The subject of the Numisheet 2025 Industrial Benchmark is a single-stage deep-drawn component, which is further processed in a trimming operation to generate the final application-related part geometry. The geometry data of the part after the cutting-induced springback is provided to the benchmark participants. The challenge is to determine as accurately as possible the required forming tool geometry of the deep drawing stage in order to obtain the provided part geometry after trimming and springback
Numisheet 2025 Industrial Benchmark