9.12: Summary
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It has been shown that energy arguments describe how cracking occurs, but that there is more than one way of working out the energy changes.
Going further
Books
A best overall book on cracking is that by Brian Lawn, Fracture of brittle solids, 1993, Cambridge University Press. You should also look at Molecular adhesion and its applications by Kevin Kendall. For the metalllurgist, the short monograph by Withers & Knott is exceptionally useful.