Comprehensive benchmark study of commercial sheet metal forming simulation softwares used in the automotive industry

There are currently several commercial Finite Element Analysis (FEA) softwares available, and it is not clear for a company the differences between them, mostly in terms of results accuracy, reliability and usability. International conferences were created to promote a world-class forum in which, simulation engineers and automakers, can exchange their knowledge in the sheet metal forming field and evaluate stamping simulation softwares, through benchmarking exercises. However, a comparison of FEA tools based in such methodology is not truly reliable, since each participant can choose its own strategy to build the numerical model based on the experimental data delivered. In this study, the authors use a different approach to achieve a more reasonable and fair comparison between three different sheet metal forming FEA tools: AUTOFORM R5.2, PAM-STAMP 2G 2012.2 and DD3IMP. Although the existence of substantial differences in the Finite Element (FE) formulations and element types, the material laws and process parameters adopted were kept as close as possible, making the constitutive models essentially identical. This benchmark was carried out using the Numisheet 2008 Benchmark #2, which is well specified and for which there are a set of experimental results available. The numerical results and experimental results were compared in terms of: punch forces, draw-in, principal strains, formability, geometry after springback and computational cost. The usage of equivalent constitutive models shows that the accuracy of the FEA tools are roughly the same. This study also highlights the true meaning of the differences between the numerical results in the industrial competitiveness of a company.