FP+DIC for low-cost 3D full-field experimental modal analysis in industrial components

Abstract

High Speed 3D Digital Image Correlation has reached notorious popularity in dynamic characterisations because of the full-field non-invasive performance. It is being especially relevant for experimental modal analysis due to the importance of the modal parameters to define the dynamic behaviour. However, the economic cost of a stereoscopic system of two high speed cameras is a main concern regarding traditional instrumentations. In the search for low-cost alternatives, different methodologies have arisen that employ a single camera for 3D measurements. One approach consists in obtaining a stereo-vision in a single image using, for instance, a mirror system. These approaches involve important field of-view restrictions. An interesting approach employs the full resolution by combining Fringe Projection and 2D-DIC for out-of-plane and in-plane displacements, respectively. In this study, this technique is explored to perform experimental modal analysis in a large non-flat aeronautical panel. The validation of the results has been performed using accelerometer measurements during an impact hammer test. The results of the study stand this technique as an attractive low-cost technique for 3D full-field modal characterisations of complex components