Non-destructive inspection of inner surfaces of technical cavities using digital speckle shearography

The application of digital speckle shearographic methods in the non-destructive inspection of the inner curved surfaces of technical cavities is presented in this paper. Experiments are carried out with defective and defect-free curved specimens and the obtained fringe patterns are analyzed. An extended theoretical formulation dealing with the slope fringe formation with respect to the inner half-cylindrical surfaces is compared with the experimentally obtained fringe patterns. Finally, the slope contours are numerically obtained by finite element analysis of defective and defect-free specimens and are compared with the experimentally obtained fringe patterns.