Kinematic Tool-Bound Profile Bending using Transformer-Tools II

• Applicants: Professor Dr.-Ing. Bernd Engel; Professor Dr. Ulf Lorenz
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 509709804

The overall objective is to increase the flexibility of tool-related profile bending processes towards partially kinematic processes by in-process adjustments of die surfaces. The forming tools are subdivided into the functional areas of "tool surface" and "load-bearing tool structure", in which the two applicants address complementary research questions. The work will be combined in joint work packages at their interface. In the functional area "tool surface", the forming mechanisms of closed profiles in contact with segmented tools were investigated in the first funding period. This led to the development of design specifications and working diagrams for the segmentation of bending tools for compression bending and rotary-draw bending. This has made the bending processes more flexible in terms of the part geometries that can be produced with a single tool set. Each segment is seen as a potential actuator, which allows not only a large change of the static contour, but also the local adjustment of the tool-related and partially kinematic shaping during the process. The second funding period will focus on investigating the interactions between the in-process segment kinematics, the resulting forming mechanisms and the resulting part properties. The goals are, on the one hand, a further flexibilization of the processes and, on the other hand, a further reduction of the forming tools. The existing working diagrams will be extended to include in-process adjustments. The methods developed will be validated in practical bending tests for selected bending tasks. The "tool structure", which is the research object of the second applicant, must therefore be able to induce these in-process segment displacements and at the same time carry the loads from the forming process. In the first funding period, modeling methods for the algorithmic design of static and moving lightweight truss-like structures were investigated using Mixed Integer Programming. In this second funding period, the work will be extended to the implementation of kinematic determinacy. The core of the methodology is to extract model-based solutions from a large number of possibilities that lead to functional bending tools in engineering practice but are near-optimal within the models. The methods developed by both applicants will be combined in the joint work packages. The aim is to develop a design method for movable bending tools that couples the forming boundary conditions with the algorithms for determining the truss structure. The results will lead to additively manufactured demonstrators of transformer tools.

• DFG Programme: Research Grants