Hole-Drilling Method for Measuring Residual Stresses

This book describes the theory and practice of the Hole-Drilling Method for measuring residual stresses in engineering components. Such measurements are important because residual stresses have a ＂hidden＂ character because they exist locked-in within a material, independent of any external load. These stresses are typically created during component manufacture, for example, during welding, casting, or forming. Because of their hidden nature, residual stresses are difficult to measure and consequently are often ignored. However, they directly add to loading stresses and can cause catastrophic failure if not properly included during engineering design. Thus, there is an urgent need to be able to identify and measure residual stresses conveniently and reliably.

The Hole-Drilling Method provides an adaptable and well-proven method for measuring residual stresses in a wide range of materials and component types. It is convenient to use and gives reliable results. Because of the hidden nature of residual stresses, the measurement method must necessarily be indirect, thus, additional care and conceptual understanding are necessary to achieve successful results. This book provides a practical introduction to the Hole-Drilling Method, starting from its historical roots and going on to focus on its modern practice. The various chapters describe the nature of residual stresses, the principle of hole-drilling measurements, procedures and guidance on how to make successful measurements, and effective mathematical procedures for stress computation and analysis. The book is intended for practitioners who need to make residual stress measurements either occasionally or routinely, for practicing engineers, for researchers, and for graduate engineering and science students.

Gary S. Schajer is a Professor in the Department of Mechanical Engineering at the University of British Columbia, Vancouver, Canada. He has extensive experience with residual stress measurements, notably the hole-drilling method using strain gauges, Electronic Speckle Pattern Interferometry (ESPI), and Digital Image Correlation (DIC). Prof. Schajer has published extensively on residual stress and related topics and recently edited the reference book Practical Residual Stress Measurement Methods. He is a member of ASTM committee E28.13 on residual stress measurement and has been responsible for three major revisions of ASTM E837 Standard Test Method for Hole-Drilling Residual Stress Measurements. Philip S. Whitehead is the Managing Director of Stresscraft Limited, located in Shepshed, Leicestershire, England. The company provides hole-drilling residual stress measurement services for academic and industrial customers, principally in the fields of aerospace and advanced material processing. Philip has 30 years of experience in the application of the strain gauge hole-drilling method and has designed and developed the many specialized hole-drilling devices used by Stresscraft. He continues to create novel drill head and strain gauge rosette designs to extend the application of the method. Current areas of interest include hole-drilling at remote features with limited access.