MIT Materials Department post-WWII fracture mechanics research (Cohen, Averbach)

Third of the three post-war fracture institutions. Tom registers his low opinion of Averbach as a 3.091 instructor.

And then the other place was MIT, here in the Materials Department. Morris Cohen and Ben Averbach. Ben Averbach was my first materials professor — that lasted for two weeks, or two recitations, where I got out of that class. He was terrible. He couldn't handle the first day of 3.091. But those are the three places where really after World War II they came to understand toughness of materials. Not that we didn't know about toughness — it had been explained by a British scientist, A. A. Griffith, back in the 1920s. He was studying the fracture of glass, and he came up with a criterion: there's a property of the material called toughness, or fracture toughness, and it's proportional to the stress applied times the square root of pi times the crack length.