| Abstract Scope |
The influence of yield function on the hole-expansion (HE) predictions is investigated for an AA6022-T4 aluminum sheet. Experiment is performed in a double-action hydraulic press with a flat-headed punch. Full strain fields are measured by a digital image correlation. Besides HE, the plastic anisotropy is characterized by uniaxial and plane-strain tension experiments. In HE, the stress state along the hoop in the hole is uniaxial tension, and it gradually changes to biaxial tension, in particular plane-strain, state in the radial direction. For the finite element simulation, Yld2000-2d anisotropic yield function is used with two parameter sets calibrated by uniaxial tension only (set 1) and both uniaxial and plane-strain tension (set 2). Only set 2 predicts a good strain field with experiment, which indicates the importance of the plane-strain mode for the adopted yield function to produce accurate HE simulations. |