Thermographic characterization of stress during crack growthA full-field-thermographic technique for imaging stress patterns in dynamically loaded structures using general purpose IR imaging and image processing hardware is described. The inspection technique is based on the thermoelastic effect. A simple geometry is examined, and the experimentally determined values for the stress invariant are shown to be consistent with theoretical and numerical calculations. The application of full-field-thermographic measurement would ensure that the observed stress field has a common sampling period, thus allowing the observation of rapidly occurring stress anomalies such as the propagation of a fatigue crack. Fatigue crack propagation in two consecutive thermoelastic stress images from an aluminum sample is shown.
Document ID
19930035686
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Cramer, K. E. (NASA Langley Research Center Hampton, VA, United States)
Dawicke, David S. (NASA Langley Research Center Hampton, VA, United States)
Welch, Christopher S. (NASA Langley Research Center Hampton, VA, United States)
Date Acquired
August 15, 2013
Publication Date
January 1, 1992
Publication Information
Publication: In: Review of progress in quantitative nondestructive evaluation. Vol. 11B; Proceedings of the 18th Annual Review, Brunswick, ME, July 28-Aug. 2, 1991 (A93-19582 06-38)