Using optical nondestructive-test methods to determine the shape and stress of a three-dimensional object

摘要

Our developments in the area of optical nondestructive-test methods using digital speckle and holographic interferometry have allowed us in the past decade to reach the state of the art in the technology of electronic-speckle interferometry systems. The knowledge obtained in this area is being used to determine the shape of an object and to characterize its strain by the three Cartesian coordinates. The behavior of piezoelectric elements under the action of an electric field of up to 500 kV/m is presented as an example. The combination of three speckle components of the strain gives the total field of the resulting strain over the entire piezoelectric surface.