Benchmarking shearographic NDT for composites

This paper reviews digital shearography in its current state of development. The technique was originally proposed as a strain measurement method but has more recently found an equally important role in the field of non-destructive testing. Digital shearography, as is currently practiced in research laboratories and in industry, reveals defects beneath the surface of an object by identifying anomalies in the field of surface displacement gradients. Shearography as a non-destructive testing toot has found innumerable applications involving a wide range of materials and, in particular, has had notable success in identifying debonds and delaminations in composite material structures. In the face of distinct advantages over other NDT methods, such as full-field view, non-contacting and real-time evaluation, and proven in a vast number of applications in the laboratory/ field/factory environment, surprisingly it does not yet have a standard, like for example an ISO International Standard. The objective of this paper is a call for the standardisation of digital shearography based on the involvement of interested parties calling for the start of the process, perhaps as is suggested here, by the technical committee TC 135 of the ISO.