Advances In Eddy Current Measurement of Residual Stress

Author:  D Barac, W Katcher, J Soules
Source:  Conf Proc: ICSP-7 (pg 326-335)
Doc ID:  1999045
Year of Publication:  1999
Abstract:  
The high frequency, eddy current response from a wide variety of common metals shows a unique signature for each sample, reflecting the particular distribution of residual stress in that sample. Individual samples are easily distinguished. A mathematical algorithm transforms the data gathered from the eddy current bridge into graphs that can be used to identify stress as a function of depth. Metals measured include aluminum, steel, titanium and several nickel-based alloys. Specific experiments demonstrate that the eddy current response is due to material stress and not other properties. Experiments in aluminum show the (reversible) effects of both tension and compression in elastically deformed samples.