Identification of the plastic behaviour in the post-necking regime using a three dimensional reconstruction technique

摘要

The aim of this paper is the identification of the plastic behaviour of a sheet metal at large strain including the post-necking regime. A tensile test was performed on a notched specimen obtained from a thick sheet metal of stainless steel. The displacement field was measured on both faces of the specimen using four cameras and stereo-correlation. From the surface data the volume displacement field inside the specimen has been reconstructed using a non linear interpolation, in such way it was possible to describe the strain localization which occurs in the centre of the specimen because of the necking. The reconstructed data have been then used to identify the hardening parameters of a Swift law using the Virtual Field Method.