The NUMISHEET Benchmark Study is an evaluation of current industry and academic research practices for predicting the outcome of challenging metal forming problems. We have now defined two different metal forming challenges and ask the metal forming community to predict what will happen and report the results by a deadline before the conference.
We will compile the submitted results and compare them with measurements from experiments. These will be made public for the first time at the conference.
Participants who do particularly well in predicting the results will be recognized at the conference.
Industrial Benchmark
Designing the forming-cutting process chain for the Mercedes-Benz T-Node
The Mercedes-Benz T-Node is the target part geometry in the NUMISHEET 2025 Industrial Benchmark — a stylized version of a lower B-pillar joint. To ensure passenger safety, the connection of the B-pillar to the undercarriage is crucial. The manufacturing of the B-pillar’s lower joint must be repeatable and precise. It is essential to derive effective tool surfaces and forming parameters to enable production within narrowly defined geometric tolerances.
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The manufacturing process in the Industrial Benchmark consists of an initial forming process; a sheet metal blank composed of 1.4301 stainless steel is used to draw the in-process-workpiece geometry of the Mercedes-Benz T-Node in a single step. Subsequently, the part undergoes trimming using a three-dimensional cutting line. The final geometry of the part is determined after springback. The provided target part geometry was obtained by scanning an actual manufactured component.
The objective of the Industrial Benchmark is to design the deep drawing and trimming operation based on the given target part geometry and material data. The evaluation criterion for the submitted results is the manufacturability of a defect-free target geometry with the highest feasible material utilization ratio. Defect categories to be avoided are tears and wrinkles. The material utilization ratio is commonly defined as the ratio of the component weight divided by the blank weight. So, the surface area of the blank used must be minimized. A material model to simulate the sheet material 1.4301, with a thickness of 1.5 mm, is provided. The participants are free to design the deep-drawing geometries and set the parameters.
The benchmark intends not to simulate the reference manufacturing process exactly but to design a stable and environmentally friendly process. The focus is on minimal thinning for reliable process control and high material utilization to conserve resources.
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.
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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
How to participate
If you would like to take part in our benchmark challenge, you can register via the following link:
After your registration you will automatically receive an e-mail with the instructions and the data set for download.
Upload your results
Use the upload buttons to send your results. Please make sure to send the files in the requested format.
20 May 2025: Deadline for uploading the benchmark results