Simulation of springback variation in forming of advanced high strength steels

Variations in the mechanical and dimensional properties of the incoming material, lubrication and other forming process parameters are the main causes of springback variation. Variation of springback prevents the applicability of the springback prediction and compensation techniques. Hence, it leads to amplified variations and problems during assembly of the stamped components, in turn, resulting in quality issues. To predict the variation of springback and to improve the robustness of the forming process, variation simulation analysis could be adopted in the early design stage. Design of experiment (DOE) and finite element analysis (FEA) approach was used for the variation simulation and analysis of the springback for advanced high strength steel (AHSS) parts. To avoid the issues caused by the deterministic FEA simulation, random number generation was used to introduce uncertainties in DOE. This approach was, then, applied to investigate the effects of variations in material, blank holder force and friction on the springback variation for an open-channel shaped part made of dual phase (DP) steel. This approach provides a rapid and accurate understanding of the influence of the random process variations on the springback variation of the formed part using FEA techniques eliminating the need for lengthy and costly physical experiments.