Hole-Drilling Residual Stress Measurements at 75: Origins, Advances, Opportunities

Since its inception by Mathar in the 1930s, the hole-drilling method has grown to be the most widely used general-purpose technique for measuring residual stresses in materials. During its history, the method has progressed greatly in both sophistication and scope, with substantial advances in all three of its main aspects. Drilling procedures have developed from the early use of a conventional low-speed drill to the modern use of high-speed orbiting endmills and, for very hard materials, abrasive machining. Deformation measurements have advanced from the use of a mechanical extensometer to strain gauges and full-field optical measurements such as Moiré, ESPI and Digital Image Correlation. Computation techniques have progressed from empirical calibrations for discrete measurements within uniform stress fields to finite-element inverse solutions for multiple measurements within non-uniform stress fields. This paper gives an overview of the history and progress of all three aspects of the hole-drilling method, and indicates some promising directions for future developments.