Experimental and Numerical Analysis on the Formability of a Heat-Treated AA1100 Aluminum Alloy Sheet

Abstract

The objective of this work is to experimentally and numerically determine the influence of plastic anisotropyon the forming limit curve (FLC) for a heat-treated (300 C-1 h) AA1100 aluminum alloy sheet. TheFLCs were obtained by the Nakajima test, where the anisotropy effect on the FLC was evaluated usinghourglass-type samples taken at 0, 45, and 90 with respect to the sheet rolling direction. The effect ofcrystal orientations on the FLC is investigated using three micro-macro averaging schemes coupled to aMarciniak and Kuczynski (MK) analysis: the tangent viscoplastic self-consistent (VPSC), the tuned strengthaVPSC, and the full-constraint Taylor model. The predicted limit strains in the left-hand side of the FLCagree well with experimental measurements along the three testing directions, while differences are foundunder biaxial stretching modes. Particularly, MK-VPSC predicts an unexpected limit strain profile in theright-hand side of the FLC for samples tested along the transverse direction. Only MK-aVPSC, with atuning factor of 0.2, predicts satisfactorily the set of FLC measurements. Finally, the correlation of thepredicted limit strains with the predicted yield surface by each model was also discussed.