High strain gradient measurements by using digital image correlation technique

When material characterization requires nonhomogeneous strain field measurements, the use of specific techniques is necessary. In this paper, the efficiency of the digital image correlation method for measuring in-plane displacements in the presence of high strain gradient is discussed. Three types of strain gradient have been studied: strain localization around a hole in a composite laminate, strain concentration at a crack tip in a TiAl alloy, and strain gradient on a polymer neck front. These three applications concern various materials, various types of loading, and various gradient values. Results demonstrate the technique capabilities for a wide range of cases.