Confronto tra alcuni programmi per la correlazione digitale di immagini basati sul principio degli elementi finiti

Digital Image Correlation (DIC) is an interesting experimental technique whose application to different problems is described in several articles. In its basic formulation, this technique prescribes subdividing the acquisition area in blocks, to process each one separately. In the last few years some new approaches, based on a Finite-Element-like area partitioning, have been proposed. The main advantage of this formulation is the continuity of the displacement field between the various blocks, but up to now, only very simple bi-linear four nodes elements have been used. In this work a new formulation, which allows to select the order and the number of nodes of the elements is described. The relative performances of the various type of elements are also discussed.