Cascade utilisation of formed components by means of geometry adjustment through free-form unroll bending

• Applicant: Professor Dr.-Ing. Bernd Engel
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 577143577

The aim of the project is to investigate a bending technology for bending already bent semi-finished products into a predictive bending geometry. This means that pre-bent components will be used as semi-finished products for further bending operations. One focus is on the bendability due to the complexity of the pre-bent components. This is due to the inhomogeneous strength and wall thickness distribution, as well as the cross-sectional deformations caused by the first bending. Based on an existing bending diagram for three-roll push bending, a bending diagram is developed in which the bending parameters of the semi-finished product and the bending parameters of the final geometry are suitably combined. In addition, the extent to which a characterization of the already bent semi-finished product in terms of geometry and mechanical properties is necessary for the process design is investigated. Firstly, a model is developed to assess feasibility, taking into account the failure modes of cracking and wrinkling. A tooling concept for clamping the parts and a process strategy are then developed. In particular, there are different strategies for forming the bend from previously bent parts that differ in the bending direction. For example, the curvature of a bend can be changed with the same direction of curvature, or it can be bent in the opposite direction by counterbending.

• DFG Programme: Research Grants