Numerically Efficient Sheet Metal Forming Simulations in Consideration of Tool Deformation

초록

In this study, an efficient numerical approach for automotive sheet forming simulation is proposed in consideration of deformation of tools. The proposed algorithm is based on sequential update of local contact state and pressure at the sheet metal-tool interfaces, which determines the deformation of tools. The material properties of both sheet metal and tool are determined from the standard tests, while the optimum numerical parameters such as tool mesh size are determined from numerical sensitivity analyses using 3-point bending and simplified benchmark problem. The proposed numerical approach is applied to the prediction of springback and draw-in of S-rail automotive part, which results in improved accuracy compared to the conventional rigid-body based forming simulation. Finally, in-depth analysis is provided for the deformation characteristics of a side-outer automotive part in the aspect of deformation in punch, die and blank holder. The analysis shows that tool deformation, particularly the blank holder deformation, is critical for forming quality of sheet metal parts, and the proposed method can be an efficient numerical scheme as an alternative to the conventional sheet forming simulation with rigid tool.

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