2D DIC-based inverse procedures for the plastic identification of sheet metals in high strain rate tests

Abstract

In this work, dynamic tension tests have been conducted by an SHB on sheet metals in order to characterize the plastic behaviour of the materials. Pictures of the samples were acquired during the test by means of a fast camera and were post-processed by a global approach 2D DIC software. On the one hand, this permitted to validate the strain measurement by the classical SHB theory formulas; on the other hand, strain distribution maps were computed with the approximation of small out-of-plane displacements. Different analytical methods have been adopted to exploit quantitatively these strain maps and to extract the parameters of a strain hardening constitutive model: the most simple method uses only the data extracted from the necking region and accounts for the cross section reduction; the most complex is represented by the VFM which uses the information provided by all the pixels in the acquired images.