Computer Modeling of Eddy Current Probability of Crack Detection
The objective of this work was to demonstrate the application of eddy current modeling to the determination of the probability of crack detection. The method of calculation, derived from previously reported work on the boundary element method (BEM) , used concepts discussed in other works on probability of detection (POD) calculations [2,3]. In contrast to the earlier POD investigations, which were concerned with crack-like flaws in flat plates with a simple circular coil as the probe, the present modeling deals with a realistic part geometry and a split-D probe configuration with ferrite cores and shield. Figures 1 and 2 show the part and probe geometries, respectively; the specifics of the inspection problem are described in the first section of this paper.
KeywordsBoundary Element Method Crack Detection Impedance Locus Impedance Boundary Condition Ferrite Core
Unable to display preview. Download preview PDF.
- 1.R. E. Beissner, “A Three-Dimensional Boundary Model for Eddy Current NDE,” in Review of Progress in Quantitative NDE edited by D. O. Thompson and D. E. Chimenti ( Plenum, New York, 1989 ), Vol. 8, p. 229.Google Scholar
- 2.R. E. Beissner, K. A. Bartels, and J. L. Fisher, “Prediction of the Probability of Eddy Current Flaw Detection,” in Review of Progress in Quantitative NDE, edited by D. O. Thompson and D. E. Chimenti ( Plenum, New York, 1988 ), Vol. 7, p. 1753.Google Scholar
- 3.N. Nakagawa and R. E. Beissner, “Probability of Tight-Crack Detection Via Eddy Current Inspection,” in these proceedings.Google Scholar
- 4.B. A. Auld, in Eddy-Current Characterization of Materials and Struc- tures, ASTM STP 722, edited by G. Birnbaum and G. Free, American Society for Testing and Materials, Philadelphia (1981), p. 332.Google Scholar
- 5.R. E. Beissner and J. A. G. Temple, “Calculation of Eddy Current Fields for Coils of Arbitrary Shape,” in these proceedings.Google Scholar
- 6.R. E. Beissner, to be published.Google Scholar
- 7.J. L. Fisher, G. L. Burkhardt, S. N. Rowland, Jr., J. H. Fitzgerald, R. J. Dexter, and J. P. Buckingham,“ Inspection Development for T-37 Wing Spar Cap Lug,” Final Report SA-ALC/MMEP/88–02, prepared for San Antonio Air Logistics Center/MMEP, Kelly Air Force Base, Texas (1989).Google Scholar