Dortmund Technical University (Dortmund, Germany):

Staupendahl D., Mag. Eng., Scientific Fellow, daniel.staupendahl@iul.tu-dortmund.de
Becker Ch., Mag. Eng., Scientific Fellow
Weinrich A., Mag. Eng., Scientific Fellow
Hermes M., Mag. Eng., Scientific Fellow
Tekkaya E. E., Prof., Dr. Eng., Head of the Institute of Forming Technology and Lightweight Construction (IUL)

Reduced production limits during the forming of new steel grades can only be overcome with the development of new production techniques. In response, several new processes were developed at the Institute of Forming Technology and Lightweight Construction of TU Dortmund University. Among these are the 3-D profile bending me thod “TSS bending”, the incremental tube forming process, the sheet metal bending process with incremental stress superposition, and the RoProFlex process, which allows the flexible production of profiles with complex cross sections from simple tubular cross sections. Process principle of incremental tube forming, RoProFlex and process principles for the extension of forming limits during free bending as well as bending force reduction during incremental tube forming and process steps of free bending with incremental stress superposition are explained. Influence of stress superposition on the spring-back beha viour of different steel grades is examined. Process kinematics of the TSS bending method and prototype with a rollbased feeding mechanism are tested. Possible application of induction heating during TSS bending to produce complex cabin structures are observed.

1. Chatti, S.; Hermes, M.; Tekkaya, A. E.; Kleiner, M.: CIRP Annals — Manufacturing Technology 59 (2010) Nr. 1, S. 315/18.
2. Staupendahl, D.; Becker, C.; Hermes, M.; Tekkaya, A. E.: New methods for manufacturing 3D-bent lightweight structures. Proc. 3. Intern. Conf. on Steels in Cars and Trucks (SCT 2011), 5.–9. Juni 2011, Salzburg, Österreich, S. 120/29.
3. Hermes, M.; Kurze, S.; Tekkaya, A. E.: Verfahren und Vorrichtung zur Umformung eines Stangenmaterials, Patentanmeldung, DE102007046870A1, 2009.
4. Hermes, M.; Staupendahl, D.; Becker, C.; Tekkaya, A. E.: Key Eng. Mat. (2011) Vol. 473, S. 37/42. 
5. Becker, C.; Hermes, M.; Wagner, R.; Tekkaya, A. E.: Verfahren und Vorrichtung zur inkrementellen Umformung von Profilrohren, insbesondere von Profilrohren mit über die Längsachse variierenden Querschnitten, Patentanmeldung, DE102010025593.9, 2010.
6. Kleiner, M.: Freibiegen mit inkrementeller Druck spannungsüberlagerung, Patentanmeldung, DE 10 2006 014 093.1, 2006.
7. Weinrich, A.; Ben Khalifa, N.; Chatti, S.; Dirksen, U.; Tekkaya, A. E.: Springback compensation by superposition of stress in air bending, Proc. 13. Intern. Conf. on Sheet Metal, 6.–8. April 2009, Birmingham, Groβbritannien, S. 621/28.