Numerical Identification of Optimum Process Parameters for Combined Deep Drawing and Electromagnetic Forming

摘要

In this paper, a method is presented for the virtual process design of combinations of deepdrawing and electromagnetic forming. With suitably chosen parameters, such processcombinations of a quasi-static and an impulse forming process extend forming limits ofclassical, purely quasi-static forming. To determine parameters leading to the desiredforming result, a numerical optimization algorithm is employed. The parameters to be adjustedcomprise parameters of the triggering current, such as frequency, amplitude, damping,etc., geometric parameters of the tool coil and parameters of the deep drawing process,as, e.g., drawing radii or tribological parameters. To reduce the required number ofevaluations of the target function, a gradient based numerical optimization scheme is employedfollowing directions of decent in the parameter space. The quality of a given parameterset is determined by computing the distance of the simulated forming result to theprescribed ideal shape via a finite element simulation. Forming limits are incorporated byso called forming limit surfaces as constraints to the optimization process, consideringrate dependence and prestrain in the second impulse forming step.