Optimization of sheet-metal forming processes using the special-purpose program AUTOFORM

Abstract Optimizing the parameters of sheet-metal forming processes requires an efficient and accurate simulation program that is able to handle real-world problems and which can be operated by a non-finite-element specialist. The program AUTOFORM is limited to the sheet-metal forming process, and fits the requirements of this process optimally. Not only is the program's technical overhead reduced to a minimum, but also the program is largely vectorizable and parallelizable and allows the use of specially developed algorithms: the number of computational degrees-of-freedom is reduced by decoupling the determination of the sheet-metal form from the flow of metal within this form. The algorithm is not only capable of taking into account the relevant bending effects but also enables more efficient iterative solvers to be used. In addition to appropriate algorithms for material behaviour, friction, blank-holder and drawbeads, the necessary accuracy is attained by using the implicit method and by adaptive mesh refinement algorithms, which allow a very fine discretization of the geometry. Using AUTOFORM, the forming processes of two real-world automotive body parts and other sheet-metal forming parts have been optimized recently by adapting parameters such as blank geometry, material, time variable blank-holder forces, and the location and geometry of drawbeads.