Application of Digital Image Correlation technique to Erichsen Cupping Test

Abstract

Digital Image Correlation (DIC) technique is a powerful and useful tool in many industrial applications for both scientific and commercial purposes. It has been widely used for mechanical tests to understand the behaviour of material. In this study, 3D DIC technique was adopted to Erichsen Cupping Test (ECT) to measure the fracture cup height and demonstrate its benefits over traditional measurement techniques. Ck75 steel sheet with various material thickness was used in the experiments. The flat specimens were fixed in a closed die set-up and stretched along two directions until fracture. All the experiments were performed on a manually operated hydraulic press with a constant cross-head displacement and recorded with high resolution cameras. Finally, to determine the fractured cup heights, the accurate and satisfactory results were obtained through DIC measurements. The full-field thickness distribution and the maximum fracture forces were also determined. Keywords: Digital Image Correlation, Erichsen Cupping Test, Stretch forming