Effect of the mechanical parameters used as input data in the yield criteria on the accuracy of the finite element simulation of sheet metal forming processes

The accuracy of the finite element simulation of sheet metal forming processes is mainly influenced by the shape of the yield surface used in the mechanical model and, in particular, by the number of input values used in the identification of the yield surface. This paper investigates the effect of the input values used for identifying the BBC 2005 yield criterion on the accuracy of the finite element predictions. The accuracy assessment of the simulation is based on the comparison of the numerical predictions obtained using the commercially available finite element (FE) code AutoForm and the experimental measurements obtained from the hydraulic bulging of sheet metals. Thickness and strain distributions, as well as the geometry of the bulged specimen were taken as comparison parameters. The accuracy of the finite element predictions obtained using the Hill-48 and Barlat-89 yield criteria is also studied and discussed in comparison with the results provided by the BBC 2005 yield criteria and the experimental data.