Short Course:
Hole-Drilling and Related RS Measurement Methods

Friday, August 12, 9:00am - 4:00pm

This workshop gives a practical introduction to material removal ("destructive") methods for measuring residual stress, with a particular focus on the hole-drilling method.  All techniques within this broad class of residual stress measurements involve: removal of some stressed material, measurement of the resulting deformations in the remaining material, and calculation of the associated residual stresses.  The simplicity and generality of this approach enables it to be applied to a wide range of specimen geometries and measurement objectives.  In addition, the primary character of the required measurements, either strains or displacements, enhances the stability and reliability of the residual stress results.

Hole-drilling is the most widely used material removal method.  It is attractive because it is simple to implement, it gives reliable results, and the small hole produced can often be tolerated or repaired.  The procedure has reached a high level of developmental maturity, and has been formally specified as an ASTM standard test method (ASTM E837).

The aims of the workshop are to give participants a clear understanding of:

• The character of material removal RS measurement methods
• How they work
• Their strengths and concerns
• How to choose an appropriate method
• How to compute residual stresses from the measured deformation data

The topics covered include:

• Survey of material removal ("destructive") methods
• The hole-drilling method and ASTM standard E837
• Measurement of stresses that vary with depth ("stress profiling")
• Generic residual stress calculations from deformation data
• Electronic Speckle Pattern Interferometry (ESPI) techniques
• Hands-on demonstation of the hole-drilling method

Full course notes will be provided.  This short course is suitable for engineers and scientists who need to make reliable and well-chosen residual stress measurements.

Course instructor:    Gary S. Schajer

Professor Schajer teaches and does residual stress research in the Department of Mechanical Engineering, at the University of British Columbia, Vancouver, Canada. His first hole-drilling publication was recognized by the 1981 Best Paper Award of the Journal of Engineering Materials and Technology. Since then, Professor Schajer has done extensive research on residual stress measurements, and has published numerous papers and book chapters. He is a member of ASTM committee E28-13 on residual stress measurement, and has been responsible for two major revisions of ASTM E837 Standard Test Method for Hole-Drilling Residual Stress Measurements.