Physics
Seminar
Wednesday, Oct. 6, 2004, 4:30 pm
Willet Science Center 101
Thomas Erber
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.