Wednesday, Oct. 6, 2004, 4:30 pm
Willet Science Center 101
Distinguished Professor of Applied Mathematics and Physics
Illinois Institute of Technology
New Developments in Metal Fatigue
Fatigue failure is a pervasive and expensive industrial hazard. Current engineering practice seeks to forestall failure with empirical service life estimates based on statistical trials even though it is well known that the data generally shows large scatter. We have developed quantitative experimental measures of the evolution of stress-strain hysteresis during fatigue cycling that narrow the scatter in fatigue life predictions, and also provide early and late warning markers of impending fatigue failure. In magnetic steels the progressive changes in the mesoscopic texture of ferromagnetic domains induced by 'cross-talk' from the accumulation of mechanical damage are large enough to be detected by flux-gate magnetometers. These piezomagnetic effects are another practical means for tracking the development of fatigue.
Please join us for light refreshments at 4:15pm outside WSC 109.