Research Group Applied Mechanics

Contact     Dr.-Ing. Till Clausmeyer

The Research Group Applied Mechanics concentrates on the competences of the Institute of Forming Technology and Lightweight Components in the fields of analytical approaches, material characterization, material modeling, and simulation for forming applications. The researchers working in these fields discuss these topics, e.g. during information sessions on mechanical and microstructural characterization methods at IUL. They support each other in related research questions. Fundamental research topics of the former Department of Applied Mechanics in Forming Technologies are addressed in the new research group since June 1. The development and application of the aforementioned methods is conducted for the forming technologies available at IUL: bulk, sheet and profile forming as well as non-conventional forming methods. The purchases of a 10 kN Erichsen UNIMAT Basic 054 tensile test machine, a servo-hydraulic Walter + Bai testing machine, and a Coxem EM-30 PLUS scanning electron microcope strengthen the competences of the research group.

Presentation of the current CIRP paper of IUL during the virtual CIRP video paper sessions

The methods supported by the research group play an important role regarding the grants acquired by IUL in 2020: DFG projects on adiabatic blanking and the analysis of continuous hot extrusion by means of similtude theory as well as an AiF project on the manufacturing of springs with the help of plasticity theory. Expertise in plasticity theory and damage mechanics are central for the research in the collaborative research center CRC 188 “Damage controlled forming processes”, in particular newly developed methods for parameter identification. The researchers present the methodological studies of the research group in scientific journals, patents, and presentation at conferences. Presenting at conferences provides the researchers with important feedback from colleagues, e.g. of the CIRP community. Dr. Till Clausmeyer explained a new analytical approach to decribe high-speed blanking processes at the CIRP video paper sessions. The width of shear bands in this process can be predicted with respect to the material properties.Important journal articles include a new testing method to determine forming limit curves at high strain rates (> 1000 /s) by Dr. Koray Demir and co-authors, new methods for the determination of yield curves under shear for large strains (> 2.5 ) by Dr. Traphöner, and an efficient method to predict the geometry during high-speed forming processes by Marlon Hahn and Prof. Erman Tekkaya. The developed method relies on elementary assumptions to decribe the dynamical forming of sheet metals, e.g. with vaporizing foils. Sheets are formed by mechanical impulses. The approach predicts the geometry with good accuracy and is approximately 10.000 times faster than a detailed modeling with complex finite-element simulations, even though it is based on simplifying assumptions. Felix Kolpak, Dr. Oliver Hering, and Prof. Erman Tekkaya invented a device for the material testing in biaxial conmpression. The patent for this invention, which enables a determination of yield curves of metallic specimens under compression from two sides, is pending. The knowledge of such flow curves is important for bulk metal forming.

The researchers in the research group could contribute to virtual conferences even though there were travel restrictions due to the coronavirus pandemic. Prof. Erman Tekkaya and Dr. Till Clausmeyer organised a minisymposium on topics related to damage control in forming processes for the first virtual international forming conference ESAFORM 2020. Several participants of IUL provided presentations and discussed with other participants at a webinar on the identification of material parameters under large strain. The webinar was organized by the Belgian company OCAS and the Belgian university KU Leuven. The collaboration of the Department of Bulk Metal Forming, researchers in the research group Applied Mechanics, and the Japanese steel manufacturer KOBE Steel and its employee Yasuhisa Taki could be continued sussessfully, even though there were temporary restrictions on the use of the lab and the metallography lab.

a) Principal sketch of forming with vaporizing foils and b) Comparison of chain model and measurements