Fabrication of a prototype of bumper beam by single point incremental forming of laser welded tailored blank and characterization of its quasi-static crushing performance

A bumper beam prototype was fabricated in the present work by deforming laser welded tailored blank (LWTB) of extra deep drawing (EDD) steels of thicknesses 1.6 mm and 1 mm through a single point incremental forming (SPIF) process. Initially, a finite element (FE) model of SPIF was developed incorporating weld zone properties, material anisotropy and experimental fracture forming limit diagram as a damage model to understand the geometrical profile and strain evolution in the prototype. Subsequently, crushing performance was evaluated numerically at three different locations along the length of the LWTB prototype using a hemispherical indenter and compared with that of the prototype of EDD 1.6 mm (BM). Results showed that the presence of thinner sections in the LWTB prototype altered the deformation mode, and the load was distributed more uniformly compared to the BM prototype during crushing. The numerically predicted deformation modes and crushing load–displacement response were validated at mid-section with experimental findings. It was concluded that the application of non-associated flow rule-based Stoughton model improved the FE-predicted results in comparison to Hill48 and YLD89 models. Approximately 9.33% and 11.28% increase in the crushing force efficiency and specific energy absorption was achieved in the LWTB prototype compared to the BM prototype. These findings revealed that the SPIF process could be applied in developing lightweight bumper beams with improved crushing performance using LWTB.

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Opracowanie rekordu ze środków MNiSW, umowa nr POPUL/SP/0154/2024/02 w ramach programu "Społeczna odpowiedzialność nauki II" - moduł: Popularyzacja nauki (2025)