ABSTRACT
It is hoped that by now the reader can agree that the primary objective of a
practical book such as this should emphasize the design and materials aspects
of fracture mechanics, on the premise that simple as well as complex struc-
tures can suffer from either man-made or nature-induced discontinuities.
The majority of cracks and flaws encountered are obviously nature controlled
and our selection of the term “crack mechanics” is meant here only to indicate
our interest in both static and dynamic response of cracks. By appropriate
design, of course, we would hope to mitigate the incidence of brittle fractur-
ing and perhaps to minimize the effect of stress concentrations. And if by now
we firmly believe in the Griffith theory of fracture, it is easy to accept the idea
that stress concentration in general is simply a mechanism for converting
strain energy into fracture energy. And the stress concentration can be
triggered by the various discontinuities such as holes, grooves, and, of course,
sharp cracks. At the same time, the probability of brittle fracture is known to
increase with an increase in the complexity of larger structures such
as bridges, ships, aircraft, pressure vessels, and large field cranes, to mention
a few.
