Structural damage identification in an aluminum composite plate by brillouin sensing

We report the results of an experimental modal analysis aimed to estimate the location of mechanical changes in an aluminum composite panel. A distributed Brillouin optical fiber sensor was used to retrieve the mode shapes of the first two bending modes of the plate. We show that the position of the defect is retrieved from the strain mode shapes, with a resolution determined by the disposition of the fiber across the structure, as well as by the spatial resolution of the interrogation unit.