24. Identification of a 3D Anisotropic Yield Surface Using a Multi-DIC Setup

Two synchronised stereo-DIC setups, referred to as a multi-DIC setup, have been used to acquire the displacement and strain fields over the front and thickness surface of a 10 mm thick high strength steel (S690QL). In a first step, using Finite Element Model Updating, the strain hardening behaviour has been identified beyond the point of maximum uniform elongation up to strains of 70%. As a result of the multi-DIC setup, full-field surface strain information is available in all three material directions: the lateral, longitudinal and through thickness direction. Consequently, a 3D anisotropic yield surface could be identified. Since the parameters of a yield surface are only identifiable if the sensitivity to these parameters is substantial, a new type of specimen has been designed having a perforation over the front and thickness surface. This double perforated specimen has then successfully been used to identify a 3D anisotropic yield surface.