The Development/Application of Sheet Metal Forming Technology at Alcoa

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. The one-step three-dimensional deformation theory of plasticity based design and the one-dimensional plane strain finite element (FEM) analysis codes have given added advantage to Alcoa to advance current part design/development technology. This article reviews the ongoing activities on applications/development of analytical modeling of sheet metal forming at the Alcoa Technical Center. The use of FEM is intended as an aid in improving the design of sheet forming process and in maximizing the formability of aluminum alloy sheet and its applications in automotive industries.