Influence of a Tensile Pre-Strain on Bending of Aluminium Alloy

Abstract:

The mechanical behavior of thin sheets of aluminium alloy 6016, of thickness 1.14 mm, was investigated in unconstrained bending, with or without a tensile pre-strain. In the case of bending without pre-strain, no rupture was observed. Therefore, a tensile pre-strain, ranging from 0.19 up to 0.45 (longitudinal strain), was applied prior to bending. The highest pre-strain values were reached within the necking area. Tensile tests on rectangular samples were performed, then reduced samples were cut out and submitted to bending. A Digital Image Correlation (DIC) system was used to measure the maximum local strains reached during both tests. The evolution of the applied load on the bending tool versus its displacement showed that a rupture in bending was obtained for tensile pre-strains higher than 0.25, as evidenced by a load drop. These results showed that very high strains can be reached in bending, which is consistent with previously obtained numerical results.

• Periodical: Key Engineering Materials (Volumes 611-612)
• Pages: 1742-1749
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.611-612.1742
• Online since: May 2014
• Authors: Sandrine Thuillier*
• Keywords: Aluminium Alloy, Bending, Mechanical Behavior, Rupture, Tensile Pre-Strain, Thin Sheet

References

[1] N. Souto, G. Andrade-Campos, S. Thuillier, Integrated methodology for the mechanical behavior of sheet metal with application to deep drawing : submitted in J. Mater. Process. Technol. (2014).

[2] N. Le Maoût, S. Thuillier, P.Y. Manach: Eng. Fract. Mech. 76 (2009) 1202-214.

[3] N. Le Maoût, Analyse des procédés de sertissage de tôles métalliques, PhD (in French), University of South Brittany (2009).

[4] S. Thuillier, J.W. Yoon, P.Y. Manach, A. Mishra, Macroscopic rupture criterion for metallic sheets under various strain paths, Plasticity'13, Nassau (Bahamas) 3-8 janvier (2013).

[5] A. Mishra, Experimental investigation and numerical prediction of rupture in bending of metallic sheets, PhD, University of South Brittany (2013).

[6] A. Mishra, S. Thuillier, Investigation of the rupture in tension and bending of DP980 steel sheet: submitted in Int. J. Mech. Sci. (2014).

[7] S. Thuillier, N. Le Maoût, P.Y. Manach: Mater. Design 32 (2011) 2049-(2057).

[8] J. Troufflard, M. Brunet, S. Thuillier: Damage in bending after tensile pre-strain of aluminium alloy sheets, report of SIMENDO predict, unpublished work (2012).