Fatigue crack growth law identification by Digital Image Correlation and electrical potential method for ductile cast iron

In this paper, a comparison between two methods used to identify fatigue crack propagation law is conducted: Digital Image Correlation (DIC) and Direct Current Potential Drop (DCPD). For this purpose, fatigue tests were conducted at R-ratio of 0.1 on a ductile cast iron commonly used for exhaust manifolds manufacturing. Results show a good agreement between the methods illustrating the accuracy of each technique for the analysis of fatigue crack growth. Moreover, an interest of DIC is also to allow studying the plasticity that occurs at the crack tip during the fatigue test.