Digital Image Correlation (DIC) is an optical, non-contact diagnostic technique that provides full-field deformation data of the surface of a solid specimen. Since the initial introduction of DIC in the 1980s, the field of DIC has developed significantly, and today, bundled commercial packages make the deployment of DIC relatively easy and straightforward. In this talk, I will present a brief synopsis of the many uses of DIC at Sandia National Laboratory. Then I will dive into a specific project focused on identifying the viscoplastic behavior (i.e. strain-rate dependence) of 304L stainless steel. Two methods of material model calibration will be compared and contrasted – a traditional technique that uses global load/displacement data from standard tensile dog bones, and the Virtual Fields Method (VFM) that capitalizes on the rich, full-field deformation data provided by DIC. To address the question of which calibration technique is “better”, finite element models of a third, independent specimen were created using each of the calibrated material models. The FE results were then validated experimentally using both global load/displacement data as well as full-field strain data. Finally, the importance of utilizing the correct boundary conditions in an FE model will be stressed.
Dr. Elizabeth Jones
Senior Member of Technical Staff (SMTS) in the Diagnostic Science and Engineering Department at the Sandia National Laboratories. Prior to joining Sandia in 2015, she was at the University of Illinois at Urbana Champaign where she received her BS, MS, and PhD in the field of Theoretical and Applied Mechanics. Her work revolves around studying the mechanical behavior of materials under complex loading conditions using Digital Image Correlation.