International Journal of Material Forming

, Volume 12, Issue 1, pp 113–122 | Cite as

Bending moment in incremental tube forming

  • E. NazariEmail author
  • D. Staupendahl
  • C. Löbbe
  • A. E. Tekkaya
Original Research


Incremental tube forming is a combination of free-form bending and spinning, which enables the direct production of curved tailored tubes under greatly reduced forming forces. To predict the effect of radial and circumferential superposed stresses, generated by the spinning rolls, on the bending moment, an analytical model is proposed. The model takes into account the isotropic hardening behaviour of the material as well as the amount of diameter and thickness reduction, simultaneously. The analytical model is validated by experimental studies with various spinning and bending parameters. The bending moment from the analytical model is used to calculate the springback. The calculated springback ratio is in agreement with experiments and shows a deviation of only 5% for the studied material.


Metal forming Incremental forming Tube bending Springback Stress superposition Tailored tubes 



This research work is kindly supported be the German Research Foundation (DFG) under the grant number TE 508/26-2. The authors additionally thank Prof. Dr. Peter Haupt for the enlightening discussions on the topic of stress-superposition.


This study was funded by DFG (grant number TE 508/26–2).

Compliance with ethical standards

Conflict of interests

The authors declare that they have no conflict of interest.


  1. 1.
    Yang H, Li H, Zhang Z et al (2012) Advances and trends on tube bending forming technologies. Chin J Aeronaut 25(1):1–12. CrossRefGoogle Scholar
  2. 2.
    Gu RJ, Yang H, Zhan M, Li H, Li HW (2008) Research on the springback of thin-walled tube NC bending based on the numerical simulation of the whole process. Comput Mater Sci 42(4):537–549. CrossRefGoogle Scholar
  3. 3.
    Jiang ZQ, Yang H, Zhan M, Xu XD, Li GJ (2010) Coupling effects of material properties and the bending angle on the springback angle of a titanium alloy tube during numerically controlled bending. Design of Nanomaterials and Nanostructures 31(4):2001–2010. Google Scholar
  4. 4.
    Al-Qureshi HA, Russo A (2002) Spring-back and residual stresses in bending of thin-walled aluminium tubes. Mater Des 23(2):217–222. CrossRefGoogle Scholar
  5. 5.
    El Megharbel A, El Nasser GA, El Domiaty A (2008) Bending of tube and section made of strain-hardening materials. J Mater Process Technol 203(1–3):372–380. CrossRefGoogle Scholar
  6. 6.
    Wang Z, Hu Z (1990) Theory of pipe-bending to a small bend radius using induction heating. J Mater Process Technol 21(3):275–284. CrossRefGoogle Scholar
  7. 7.
    Hu Z (2000) Elasto-plastic solutions for spring-back angle of pipe bending using local induction heating. J Mater Process Technol 102(1–3):103–108. CrossRefGoogle Scholar
  8. 8.
    Tozawa Y, Ishikawa T (1988) A new tube bending method — application of ‘bend-rolling process’. CIRP Ann Manuf Technol 37(1):285–288. CrossRefGoogle Scholar
  9. 9.
    Nakamura M, Maki S, Nakajima M et al. (1996) Bending of Circular Pipe Using a Floating Spherical Expanding Plug. In: Advanced Technology of Plasticity 1996: Proceedings of the 5th International Conference on Technology of Plasticity, pp 501–504Google Scholar
  10. 10.
    Chatti S, Hermes M, Tekkaya AE, Kleiner M (2010) The new TSS bending process: 3D bending of profiles with arbitrary cross-sections. CIRP Ann Manuf Technol 59(1):315–318. CrossRefGoogle Scholar
  11. 11.
    Becker C, Staupendahl D, Hermes M et al. (2012) Incremental Tube Forming and Torque Superposed Spatial Bending - A View on Process Parameters. Steel Research International Special Issue: 415–418Google Scholar
  12. 12.
    Hermes M, Kurze B, Tekkaya AE (2008) Verfahren und Vorrichtung zur Umformung eines Stangenmaterials: Method and device for forming a bar stock, bar stock.
  13. 13.
    Becker C, Tekkaya AE, Kleiner M (2014) Fundamentals of the incremental tube forming process. CIRP Ann Manuf Technol 63(1):253–256. CrossRefGoogle Scholar
  14. 14.
    Becker C, Tekkaya AE (2015) Wall Thickness Distribution during a Combined Tube Spinning and Bending Process. KEM 651-653:1614–1619.
  15. 15.
    Haupt P (2002) Continuum Mechanics and Theory of Materials, Second edition. Advanced Texts in Physics. Springer Berlin Heidelberg, BerlinCrossRefGoogle Scholar

Copyright information

© Springer-Verlag France SAS, part of Springer Nature 2018

Authors and Affiliations

  1. 1.Institute of Forming Technology and Lightweight Components (IUL)TU Dortmund UniversityDortmundGermany

Personalised recommendations