Robust optimization strategies for sheet metal springback compensation

Sheet metal forming is a major industrial process, mainly due to its cost efficiency after the establishment of the process design. However, the process design from tools geometry to load conditions is not straightforward, as a consequence of the side effects associated with sheet metal forming. The emphasis in this area goes to the springback effect or elastic recovery, which is one of the main causes of part’s inaccuracy, demanding tool compensation. This work proposes to compare different robust optimization strategies to sheet metal forming springback compensation. The methodology adopted resorts to Response Surface Method (RSM), as well as to Finite Element Model Updating (FEMU) strategies, to adjust the design variables. These include the tools’ surfaces, which are parametrised with NURBS. These strategies are then compared using the U-Rail benchmark. The results achieved reveal a reduction of 99% on the geometrical error of the final piece for the best methodology.