Strain measurement by three-dimensional electronic speckle pattern interferometry: potentials, limitations, and applications

Principles and new developments of 3-D electronic speckle pattern interferometry (3-D ESPI) for strain and stress analysis are presented. The potentials and limitations are discussed, and some applications used in industry are shown. The newly developed 3-D ESPI technique allows rapid measurement of both the shape and the 3-D deformation of complex industrial components. The combination of shape and deformation provides all the necessary data for the accurate and quantitative determination of true strain and thus stress on nearly any industrial component. Based on a lightweight compact sensor design and new glass fiber concepts, the new device has been greatly miniaturized and can be easily attached to the components during testing. It is well suited for the harsh environmental conditions often found in the real test world.