Characterizing the Elastic Behaviour of a Press Table through Topology Optimization

Sheet metal forming in the car industry is a highly competitive area. The use of digital techniques and numerical methods are therefore of high interest for reduced costs and lead times. One method for reducing the try-out phase is virtual rework of die surfaces. The virtual rework is based on Finite Element (FE) simulations and can reduce and support manual rework. The elastic behaviour of dies and presses must be represented in a reliable way in FE-models to be able to perform virtual rework. CAD-models exists for nearly all dies today, but not for press lines. A full geometrical representation of presses will also yield very large FE- models. This paper will discuss and demonstrate a strategy for measuring and characterizing a press table for inclusion in FE-models. The measurements of the elastic press deformations is carried out with force transducers and an ARAMIS 3D optical measurement system. The press table is then inverse modelled by topology optimization using the recorded results as boundary conditions. Finally, the press table is coupled with a FE-model of a die to demonstrate its influence on the deformations. This indicates the importance of having a reliable representation of the press deformations during virtual rework. (paper)