Determination of Sub-Surface Distributions of Residual Stresses by a Holographic-Hole Drilling Technique

Abstract

A method is described for combining incremental hole drilling with holographic interferometry to determine the distribution of in-plane residual stresses as a function of depth below the surface. The computational 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 feasibility of obtaining results at greater depths by drilling a large hole directly over a preceding smaller one is demonstrated.