Electronic speckle pattern interferometry applied to the displacement measurement of sandwich plates with two ‘fully potted’ inserts

The experiments of electronic speckle pattern interferometer (ESPI) successfully applied to sandwich plates with two inserts has been earliest presented in this paper. Proposed ESPI has advantages of full-field and non-destructive testing, which can measures microscopic out-of-plane displacement in the elastic region without wasting specimen. For validation purpose, the finite element method (FEM) analysis was conducted. By comparing the results of ESPI and FEM displacement fields around the inserts, a convincing agreements is revealed. The effect of insert spatial interval on the deformation of two-inserted sandwich plates was obtained by the ESPI and FEM: the wider the spatial interval of the two inserts is, the bigger the out-of-plane displacement at the insert center of sandwich loaded by the same force is.