Defect depth estimation using pulsed eddy current with varied pulse width excitation

• Published in: Insight (Northampton) Vol. 51; no. 2; pp. 69 - 72
• Main Authors: Abidin, I Zainal, Mandache, C, Tian, G Y, Li, Yong
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Northampton British Institute of Non-Destructive Testing 01.02.2009
• Subjects: Analysing. Testing. Standards; Applied sciences; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Industrial metrology. Testing; Materials science; Materials testing; Measurement and testing methods; Mechanical engineering. Machine design; Metals. Metallurgy; Nondestructive testing; Physics; Solid mechanics; Structural and continuum mechanics; Testing for defects; Electric conductors; Pulse width; Nondestructive testing; Structure integrity; Electromagnetic pulses; Low frequency; Defect characterization; Electrical measurement; Discrimination; Defect size; Assembling; Modelling; Electromagnetic testing; Localization; Pulses; Pulse current; Defect detection; Eddy current testing
• ISSN: 1354-2575; 1754-4904
• DOI: 10.1784/insi.2009.51.2.69

Current industry requirements demand defect quantification rather than simple defect detection. Besides the defect geometrical size, its depth location plays a critical role for the integrity of a structure and the safe life operation of the overall assembly. It has been long known that pulsed eddy current (PEC) non-destructive testing (NDT) for electrically conductive materials has the advantage of gathering different depth information in a single excitation process. This fact is due to the low frequencies found in the pulse spectrum that is used for the excitation of the driving coil; however, quantifying the defect depth still remains a challenge. This study considers different pulse widths and frequency components as a method of defect depth discrimination with direct applications in the evaluation of corrosion defects in multi-layer aircraft structures. Experimental testing and numerical modelling approaches are concomitantly discussed as ways of defect depth quantification.