Abstract:The main objective of this work was to experimentally and numerically evaluate the forming limit curve (FLC) of aluminum alloy 2B06. The FLC of 2B06 was measured by conducting the hemispherical dome test with specimens of different widths. The theoretical predictions of the FLC of 2B06 were based on the different instability theories and different yield functions. The comparison results show that the influence of the different yield functions can be ignored and the FLCs are basically same utilizing different yield functions based on the specific instability theory. While there is a significant difference among theoretical prediction curves based on three instability theories and the same yield function. The FLC based on SWIFT’s diffuse instability theory is higher than the measured curve. The right part of FLC based on HILL’s localized instability theory is invalid. The theoretical prediction curve based on M-K theory agrees well with the measured FLC. So, the theoretical curves based on M-K theory are effective for predicting the forming limit.

Key words: forming limit curve; M-K theory; theoretical prediction; aluminum alloy 2B06; fracture; yield functions