FEM simulation of the forming of textured aluminum sheets

A texture-based fourth order strain-rate potential was used directly in an elastoplastic finite element code (ABAQUS) to model sheet metal forming. The method is based on the Taylor model of crystal plasticity and therefore takes the presence of texture into consideration. The deep drawing of cold-rolled and annealed aluminum sheet was simulated using this code in conjunction with a specially developed UMAT subroutine. The full geometry of deep drawing, including the disposition of the tools and the effect of friction, was taken into account in the simulations and both shell and brick elements were employed. The influences of element type, as well as of friction and blank holder force, are discussed. The thickness variations induced by deep drawing are also described. Reasonable agreement was obtained between the predicted and measured earing profiles for an annealed aluminum sheet. The steps to be followed to bring about further improvements in the accuracy of the simulations are also discussed.