SPRINGBACK COMPENSATION IN THE PRODUCTION OF FORMED SHEET-METAL PARTS

• Main Authors: HAAGE, Stefan, HARTMANN, Benjamin, BIRKERT, Arndt, STRAUB, Markus
• Format: Patent
• Language: English; French; German
• Published: 28.11.2018
• Subjects: CALCULATING; COMPUTING; COUNTING; ELECTRIC DIGITAL DATA PROCESSING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; PERFORMING OPERATIONS; PHYSICS; PUNCHING METAL; TRANSPORTING; WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS ORPROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL

A method for determining an active surface of a forming tool for producing a complex formed part with a target geometry by performing a drawing type of forming process on a workpiece comprises a simulation of a forming operation on the workpiece by means of a zero tool for creating a first configuration of the workpiece, a simulation of an elastic springback of the workpiece from the first configuration into a second configuration that is largely free of external forces, and also a calculation of a deviation vector field with deviation vectors between the first configuration and the second configuration. In the method, a non-linear structural-mechanical finite element simulation is carried out on the workpiece. By the non-linear structural-mechanical finite element simulation, the workpiece is deformed from the first configuration or the second configuration into a target configuration by using deviation vectors of the deviation vector field. The following steps are thereby carried out: defining at least three fixing points of the first or the second configuration, wherein the fixing points are intended to remain unchanged with respect to their position during the non-linear structural-mechanical finite element simulation; fixing the first configuration or the second configuration at the fixing points; approximating the configuration of the workpiece to the target configuration outside the fixing points by means of calculation of forces or displacements while taking into account the stiffness of the workpiece until the target configuration is achieved; and specifying the achieved target configuration as the active surface for the forming tool. A method for producing a forming tool, a complex formed part and a corresponding computer program product are likewise described.