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Crack Dynamics

March 9, 2006

Almost any brittle material can crack, whether it’s a drinking glass or the crust of the Earth. But while cracking is something we see everywhere, it’s very difficult to study scientifically.

Transcript

BOB HIRSHON (host):
The science of cracking up. I’m Bob Hirshon and this is Science Update.

A small crack in a crucial part could crash a computer or even an airplane. Yet cracks of all kinds – from broken glass to faults in the Earth – have been notoriously tough to understand. MIT engineering professor Markus Buehler says that’s because the big picture of a crack depends on the behavior of individual atoms ripping apart.

MARKUS BUEHLER (MIT):
So there’s this challenge of coupling this large scale, which engineers are interested in, with the scale of a few atoms.

HIRSHON:
Using computer simulations, he and his colleagues found that right at the cracking point, the atomic bonds in the material radically change. Brittle materials actually soften, while flexible materials get stiffer. Understanding how that affects the whole fracture may lead to better models of everything from semiconductor failures to earthquakes.

I’m Bob Hirshon, for AAAS, the science society.