Estimation of masonry mechanical characteristics by ESPI fringe interpretation

Electronic speckle pattern interferometry (ESPI) can be a powerful tool for efficient non-destructive testing and evaluation of micro-deformations of masonry materials and structures. Unlike traditional transducers, ESPI requires no direct contact with the object, and the full-field visualisation it offers provides for a better understanding of the surface behaviour. This paper describes an in-plane deformation inspection system which has been built up for an automatic acquisition of interferograms at different stages of a test. The system is applied to the evaluation of some mechanical characteristics of masonry components. Qualitative and quantitative results are obtained and an overall discussion is presented.