Professor Ted Brzinski and his former postdoctoral adviser, NCSU professor Karen Daniels, studied the sound waves that precede stick-slip transitions in friction.
Brzinski and Daniels recently published an article in Physical Review Letters that has been featured in a Focus in Physics. In this work they studied a granular material that was subjected to a steadily increasing shear stress between parallel walls until the material failed (much like the geometry and dynamics of an earthquake). By quietly listening to the system before and after these "labquakes", they demonstrated a novel approach to characterizing the evolving state of the material. Their work is suggestive of an approach to forecasting sudden failures of amorphous solids, like earthquakes or avalanches."
