Fundamental Research and Process Development for the Manufacturing of Load-Optimized Parts by Incremental Forming of Metal Sheets – Incremental Sheet-Bulk Metal Forming (iSBMF)

Funding: German Research Foundation (DFG)
Project: CRC/TR 73 • Subproject A4
Contact: Dr.-Ing. Sebastian Wernicke

The main objective is the manufacturing of geometrically complex components from sheets with integrated functional elements by incremental forming.

After adjusting the load capacity by thickening of the edge (see Figure a) the calibration of functional elements follows. As a fundamental question, it has to be investigated whether the strain paths resulting from different process strategies are usable for a targeted manipulation of the mechanical product properties. Numerical investigations of the iSBMF processes present cyclic load changes. Measurements of the resulting hardness reveal that iSBMF is not able to transform the strain hardening potential of the material observed in material characterization with monotonous loading. The consideration of cyclic strain hardening by a simplified modeling approach increases the quality of the force prediction by 55% compared to utilizing flow curves determined during monotonous loading (see Figure b). Therefore, taking kinematic hardening into account is identified to be essential for the numerical process design of iSBMF.

a) Schematic of experimental setup, b) Resulting forming force comparison