DETERMINATION OF SUBSURFACE DISTRIBUTIONS OF RESIDUAL-STRESSES BY A HOLOGRAPHIC-HOLE DRILLING TECHNIQUE

A method is described for combining incremental hole drilling with hol ographic interferometry to determine the distribution of in-plane resi dual stresses as a function of depth below the surface. The computatio nal foundation of the method is summarized. Results of experiments to check the ability of the method to determine two different sub-surface stress distributions are given. Utilizing the same hologram, the feas ibility of obtaining results at greater depths by drilling a large hol e directly over a preceding smaller one is demonstrated.