Identification of the YLD2000-2D model with the virtual fields method

Abstract

In this paper an inverse method, the virtual fields method (VFM), is used to identify the parameters of an anisotropic plasticity model, the Yld2000-2D yielding criterion. Digital image correlation (DIC) is used to measure the strain field over the specimen surface. In particular, the developed experiments are intended to investigate a region of the yielding surface close to the plane strain condition. As first step, the YLD2000-2D yielding criterion is implemented in the VFM framework for large strain plasticity. Afterwards, experiments are performed on steel sheet coupons and the proposed method is used to identify the constitutive parameters. The specimens are designed in order to guarantee a good compromise between the aspect ratio and the spatial resolution of the DIC measurement. In order to look at the anisotropic behaviour, the specimens are cut in different orientations with respect to the rolling direction. The results achieved with the VFM using Yld2000-2D are compared with the identification performed using the Hill48 model. The identified results are also compared with reference values obtained from standard tensile tests.