Combined shearography and speckle pattern photography for single-access multi-component surface strain measurement

摘要

Full surface strain measurement requires the determination of two out-of-planeand four in-plane displacement gradient components of the surface strain tensor.Shearography is a full-field speckle interferometry technique with a sensitivitypredominately to the out-of-plane displacement gradient. Speckle patternphotography has the sensitivity to the in-plane displacement, and taking thederivative yields the in-plane displacement gradient. In this paper the twotechniques are combined to yield a single-access multi-component surface strainmeasurement using shearography to measure the out-of-plane components andspeckle pattern photography to measure the in-plane components. Results arepresented of a multi-component surface strain measurement.