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The advent of high speed computers permits the use of the finite element method to model complex sheet metal forming processes on a reasonable time scale. The design and development of sheet metal parts in the automotive industry and the need for improved sheet forming processes and reduced part development cost have led to the use of computer simulation in tool/die design of sheet metal pressings. An accurate constitutive description of plastic anisotropic yield loci and work hardening of material behavior in sheet forming is now a reality. The constitutive equation developed at Alcoa for describing anisotropic material behavior is consistent with polycrystalline plasticity, and it is expected to improve the computational accuracy of forming process for polycrystalline metals and alloys.

Deep drawing experiments using rectangular pans, made of aluminum alloys, have been conducted at the Engineering Research Center for Net Shape Manufacturing (ERC/NSM) at the Ohio State University. A 160 ton Minster hydraulic press was used for the experiments. A 3-D finite element code called PAM-STAMP was used in the simulations. The current study investigates the effect of blank holder force control and blank shape on the final product quality. In the hydraulic press, it was possible to control the blank holding force (BHF) as a function of time. By conducting experiments and simulations using three blank shapes and various BHF profiles, it has been shown that blank shape and the BHF have significant effect on the formability of aluminum alloy pans, and they must be optimized to eliminate wrinkling and fracture. A decreasing BHF profile was shown to be effective in improving part quality and practical for use in industrial applications.