I have updated my notes on "Energe Release Rate. Fracture Energy". I will use my twitter account to update my teaching, research, and reading. You will get an automatic update if you subscribe to my twitter account.
The qualitative picture of fracture may be well-understood, across disparate scales of length and time, from the distortion of electron clouds, to the jiggling of atoms, to the motion of dislocations, to the extension of the crack, to the load-carrying capacity of a structure. This statement by itself, however, is of limited value: it offers little help to the engineer trying to prevent fracture of a structure. Hypes of multiscale computation aside, no reliable method exists today to predict fracture by computation alone.
A pragmatic approach is to divide the labor between numerical computation and experimental measurement. Some quantities are easier to compute, and others easier to measure. A combination of computation and measurement solves problems economically.
Of course, what is easy changes when circumstances change. As new tools and applications emerge, it behooves us to renegotiate a more economical division of labor. The history of fracture mechanics offers excellent lessons on such divisions and renegotiations. The evolution of fracture mechanics is better appreciated historically and economically.
I hope to hear your views on the development of fractue mechanics, both historical and emerging trends.