from the conferences organized by TANGER Ltd.
To evaluate formability in sheet metal forming, experimentally determined Forming Limit Curves (FLC) are often used. These conventional curves represent the forming limits of a material. The most widely used approach to experimentally determine the onset of necking of sheet metals is formulated in EN ISO 12004-2. The first goal of this work is to investigate limit strains for dual phase steel HCT490X with nominal thickness 0.6 mm. The second goal is to evaluate influence of strain rate on position of forming limit curve also for material HCT490X. The FLC curve has been measured through Nakajima test on universal testing machine. The test set-up and the shape of samples result from EN ISO 12004-2. Unrepeatable, isotropic and highly contrast pattern was applied on samples and was measured using 3D photogrammetric system ARAMIS by GOM. The punch movement velocity was gradually changed and experimentally measured forming limit curves are compared in this paper.
Keywords: Strain rate, sheet metal forming, forming limit curve, nakajima test, dual phase steel© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.