Comparison of Local and Global Approaches to Digital Image Correlation

Local and global approaches to digital image correlation are compared when the displacement interpolation is based upon bilinear shape functions (i.e., with four-node quadrilaterals). The resolution in terms of displacements and strains associated with both techniques are evaluated a priori and validated a posteriori by using series of images of real experiments. It is shown that global approaches generally out-perform a local approach.