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Authors: Robert R. Hughes (University of Bristol) , Bruce Drinkwater (University of Bristol)
The service lifetime of industrial components relies on an understanding of the size, location and orientation of defects present in the materials. This is often over-estimated due to inadequate methods of identification and characterisation in NDE techniques. Multi-frequency eddy-current measurement methods offer a promising way of obtaining sufficient information to accurately characterise and size surface-breaking defects. In this study a parametric-manifold database search approach is employed to low-MHz range eddy-current impedance spectra measurements, to characterise such defects. An in-house, air-cored solenoid coil sensor was used to inspect for surface-breaking defects and a hybrid finite-element and equivalent-circuit model was developed to simulate the impedance over a range of frequencies around it’s electrical resonance. The hybrid-model was optimised, calibrated and validated against experimental standoff/thickness measurements demonstrating accuracy over small standoff distances. The model was used to simulate a database of 2D scans of surface breaking notches over a range of frequencies and a principle component parametric-manifold approach was employed to evaluate the sensitivity of the sensor and frequency range. Finally, simulated and experimental defects were characterized in Titanium 6V-4Al and Aluminum.
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How to Cite: Hughes, R. R. & Drinkwater, B. . (2019) “Exploring parametric-manifolds for eddy-current defect characterisation”, Review of Progress in Quantitative Nondestructive Evaluation.(0).