Effects of Higher Order Terms in Fracture Mechanics of Shape Memory Alloys Bydigital Image Correlation

The Digital Image Correlation techniquewas applied in this work to study the fracture properties of a commercial NiTipseudoelastic alloy. In particular, the near crack tip displacement field of a single edge crack specimen was measuredand the stress intensity factor was estimated by using a proper fitting procedure based on the William's series expansion. Furthermore, the effects of higher order terms in the William's series, the so called T-stress, were analyzed for different sizes of the crack-tip fitting region and results were compared with analytical predictions. Results revealed that digital image correlation is a powerful tools for evaluating displacement fields in the crack tip region and to estimate the effective fracture control parameters of a NiTipseudoelastic alloy.