Material- and failure characteristics for high-speed forming and cutting

• Applicants: Professor Dr.-Ing. Alexander Brosius; Dr.-Ing. Verena Psyk
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 316056392

The aim of the project is to develop a method for determining material and failure characteristics for processes with high strain rate. Thus, the numerical analysis and design of production processes with high forming speeds can be significantly improved compared to the state of the art and a decisive contribution can be made to the utilization of known process-specific advantages in industrial production. In the first funding period, a combined numerical and experimental approach was realized and researched. It was proven that the developed experimental setups and an inverse parameter identification system can be used to determine material parameters for forming speeds of up to 5∙104/s. The material parameters show significant differences for different stress states, an effect that does not occur under quasi-static loading.The approach will now be extended in order to consider the influence of adiabatic heating and the associated local reduction in yield stress. In particular, it must be clarified to what extent differences can be attributed to different heating of the material during the test. For this purpose, a combined numerical and experimental approach is pursued. In detail, the material model is extended in the simulation by a temperature dependence and then used for the inverse determination of the purely strain rate dependent material parameters. This enables a separation of the superimposed and oppositely acting influences of forming speed and temperature on the material behavior.The extended method for determining material parameters will be comprehensively validated. Initially, IWU will perform tests at different temperatures at on a hydraulically driven high-speed testing machine. Based on this, further verification is done using technological tests with different stress states. FF considers a high-speed deep-drawing process, while IWU puts the focus on high-speed cutting. Finally, the data is consolidated in a synthesis step and prepared in such a way that it can be provided as open data.

• DFG Programme: Research Grants
• Co-Investigator: Dr.-Ing. Matthias Nestler