Effect of different anisotropic 3D yield functions on a roller hemming simulation

For sheet metal forming simulations, it is frequently sufficient to consider only the plane stress conditions. However, for certain applications like bending with small radii, thick sheets or special forming processes, e.g. hemming, wall ironing and roll forming, neglecting the stresses ?33, ?13 and ?23 is not a workable solution to obtain accurate and reliable results. Hence, the full stress state has to be taken into account to improve the simulation quality.