DIC‐measurement during tensile testing and its approach for the FEM‐simulation of "Die‐Less‐Hydroforming". Issue 1 (18th November 2019)

• Record Type: Journal Article
• Authors: Metzger, Andreas; Ruff, Daniel C.; Ummenhofer, Thomas
• Other Names: Eberhardsteiner J. guestEditor.; Schöberl M. guestEditor.
• Is Part Of: Proceedings in applied mathematics and mechanics. Volume 19:Issue 1(2019)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-11-18
• Subjects: Applied mathematics -- Periodicals; Engineering mathematics -- Periodicals; Mathematical physics -- Periodicals; 519
• DOI: 10.1002/pamm.201900443
• Languages: English
• ISSNs: 1617-7061

Abstract

Abstract: Digital Image Correlation (DIC)‐measurement is an optical measurement method which enables contactless and area‐wide continuous acquisition of 3D‐geometry, deformation and surface strain during experimental investigations. Within Die‐Less‐Hydroforming, an increasing innovative forming technology, see [1] and [2], the DIC‐measurement may be used for two tasks at once: The forming process of Die‐Less‐Hydroforming can be investigated continuously within the scope of the classical application of DIC in terms of geometry and deformation acquisition. However, this paper focuses on the use of DIC during the uniaxial tensile test of sheet metal used for manufacturing the double‐layered Die‐Less‐Hydroforming‐blank. Using DIC during the tensile test facilitates to measure the current cross‐section area continuously which allows the determination of a true stress‐true plastic strain‐curve. This curve is required as input for FEM‐forming‐simulation to achieve significant results. But with conventional testing methods, for the case of flat tensile test specimens, it cannot be determined beyond uniform strain A g . Therefore, the "true" values beyond A g are often estimated by mathematical approximations.