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Preface
e Hole-Drilling Method is the most widely used relaxation type method for measuring resid-
ual stresses. Since its inception in the 1930s, the technique has dramatically grown and devel-
oped, with important new advances continually reported. e size and continued vitality of the
research literature on the subject testifies to the fertility and rich potential of the technique. Josef
Mathar, to whom this book is respectfully dedicated, would have had good reason to be proud
of the evolution of his elegant concept. It is very unfortunate that his life was cut short so that
he did not live to see the early flowerings of his foundational work.
While it may be said that the Hole-Drilling Method has one ancestor, it also has very
many family members, each of whom brings an important and diverse contribution to the tech-
nique. Josef Mathar certainly laid down the foundation of the method, in his published work he
also conceptually anticipated both the Ring-Core and Deep-Hole methods. However, the great
strength of the Hole-Drilling Method derives from the numerous subsequent workers who sub-
stantially and very skillfully expanded the concept. It was they who made it into the robust and
practical technique that it is today.
e authors are among the hole-drilling “family members,” each with experience of the
method extending over many years. It is our wish to share this experience with interested readers
and thereby contribute to the wider use of the Hole-Drilling Method and to its ongoing devel-
opment. is book is primarily intended as a practical handbook, although it is also hoped that
it will find good secondary use as a reference textbook. e target audience is measurement prac-
titioners, practicing engineers and students. In support of their needs we have endeavoured to
make the book contents as accessible as possible, while seeking to maintain a rigorous technical
standard. In this respect, our objectives parallel the idea indicated the title of a totally unrelated
work, e Prepared Table, a classical book of religious law written in the 16th century by Joseph
Karo. Neither of us have read the very specialized content, but the mental image conjured by
the inspired title vividly demonstrates the need to present a written work in a well-laid out and
accessible way analogous to how one would arrange the food on a dinner table for a welcome
guest. It is the task of the host to prepare the table so that the guest will find well-made and sat-
isfying things ready for them. We have endeavoured to achieve this objective within this book.
How well we may have succeeded will be up to the reader to judge. In places where we have
fallen short, it is hoped that a generous allowance may be granted.
e substantial size and variety of the hole-drilling literature has made it very challenging
for us to arrange our prepared table. ere are so many “foods” that we could serve, but excess
provision brings serious risk of indigestion. us, we have tried to follow a “keep it simple”
approach where we focus on the basic information. Each chapter also includes a thematic list