Investigations of the springback compensation on air bending with incremental stress superposition

• Applicant: Dr.-Ing. Frauke Maevus
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2007 to 2015
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 39727461

Innovative lightweight technologies are more important than ever because of rising energy and raw material costs. For the implementation of lightweight high-strength thin-walled structures, sheet materials with constant or variable thickness offer numerous advantages over common materials. Forming these materials represents a high problem. Because of their comparatively high amount, and usually unknown springback, larger shape and dimensional variations occurs, so a subsequently calibration and post-processing processes are required. This is particularly true for air bending, which has found wide industrial application due to its high flexibility.In this project, technological options are examined to reduce the amount of springback significantly by applying the new method "air bending with incremental stress superposition". A particular feature and advantage of this new variant is the local compressive stress superposition in the forming zone. This results in a local springback compensation. Due the movement of the roll through the bending line, a constant bending angle can be achieved. Since this method neither requires expensive tools nor a complex control, it provides a flexible and cost effective alternative to other methods for forming of lightweight materials.For a reliable production of tailor-made and perfectly contoured bent parts by air bending with incremental stress superposition, a deep understanding of the process is required. So a detailed knowledge of the processes taking place during the stress superposition is needed. In the process both the achievable accuracy and quality of the component have to be well known in advance. The same is true for the applications and manufacturing limits in order to demonstrate the industrial application suitability for the bending of both thin sheets of high-strength materials and tailored blanks.So the objective of the project is the scientific development of fundamental knowledge and its implementation in a novel bending method. This novel process gives the possibility to manufacture flexible and economical innovative lightweight components made of new materials produced at a high level of quality.

• DFG Programme: Research Grants
• Participating Person: Dr.-Ing. Sami Chatti