OPTIMIZATION OF SHEET-METAL FORMING PROCESSES USING THE SPECIAL-PURPOSE PROGRAM AUTOFORM

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 spec ialist. The program AUTOFORM is limited to the sheet-metal forming pro cess, and fits the requirements of this process optimally. Not only is the program's technical overhead reduced to a minimum, but also the p rogram is largely vectorizable and parallelizable and allows the use o f specially developed algorithms: the number of computational degrees- of-freedom is reduced by decoupling the determination of the sheet-met al form from the flow of metal within this form. The algorithm is not only capable of taking into account the relevant bending effects but a lso enables more efficient iterative solvers to be used. In addition t o appropriate algorithms for material behaviour, friction, blank-holde r and drawbeads, the necessary accuracy is attained by using the impli cit method and by adaptive mesh refinement algorithms, which allow a v ery fine discretization of the geometry. Using AUTOFORM, the forming p rocesses of two real-world automotive body parts and other sheet-metal forming parts have been optimized recently by adapting parameters suc h as blank geometry, material, time variable blank-holder forces, and the location and geometry of drawbeads.