Computer aided analysis and design of sheet metal forming processes: Part II – Deformation response modeling

The continually decreasing lead-times for the design approval and the production of stamping dies enforce the stamping methods engineer to apply the finite element method more effectively in the industrial settings. The selection of a proper finite element plasticity model and the efficient utilization of the material formability data are main factors controlling the accuracy of the sheet metal deformation response prediction using a computer simulation code. Especially with the introduction of high strength sheet metals in to the stamping processes the capabilities and limitations of a plasticity model used in finite element process simulations should be reevaluated in order to have an accurate assessment of the part formability and springback deformations. In this part of the study, following a review of the sheet metal deformation properties in conjunction with the initial yield loci and plastic anisotropy concepts, two rate-independent anisotropic plasticity models are employed in the deformation modeling of a stamping part. Their performances in the formability and springback analyses are demonstrated and comparisons are presented.