Numerical prediction and experimental validation of forming limit curves of laminated half-hard aluminum sheets

Considering the recent and widespread use of half-hard rolled aluminum sheets in various industrial sectors, this study aims to characterize, determine and evaluate the formability of these sheets. The first phase is to experimentally determine the forming limit curve of laminated half-hard aluminum sheet AA1050-H24. The FLC is determined experimentally from the limiting strain values measured at the fracture location of the specimen using the Nakazima test. Different geometries of the laminated sheet were produced to obtain different deformation paths in the plane of the main deformations. However, experimentally determining a forming limit curve is very time intensive and requires dedicated and costly equipment. The second phase is to develop an alternative method to replace the experimental protocol. Indeed, we will propose a hybrid approach between the finite element method and necking criterion for determining the onset of localized necking in order to numerically predict this curve. In order to make a numerical prediction, Abaqus/Explicit was used to perform finite element modeling of the Nakazima test. The necking criterion based on the first component of the limit strain was used the time of appearance of necking and to plot the forming limit curve. A comparison of the experimental and numerical results is carried out to determine the effectiveness of the necking criterion in the numerical evaluation of the formability of aluminum sheet AA1050-H24. The necking criterion can numerically evaluate the formability of the AA1050-H24 sheet.