Development of Eddy Current Testing System for Complicated-Shaped Components

Abstract

The objectives of this study are to develop a new inspection probe for complex structures using eddy current testing method (ECT), to establish the recognition technique of real ‰aw shape such as stress corrosion cracking (SCC), and to develop a rapid nondestructive inspection system. An ECT system consists of measurement and computational modules that are connected via a network circuit. The measurement module includes a ‰exible ECT sensor, which couldˆt on the curvature surface of radius larger than 25 mm with a mechanical manipulator. The computational module is used for SCC sizing. It includes a database of ECT signals that are used to execute numerical calculations. SCC sizing can be evaluated by comparing the measured ECT signals with the calculated ECT signals within the database. We have demonstrated that the system could be used to estimate the SCC length and depth sizing in 140 s. The accuracy of length sizing showed an RMS error of 3.7 mm and the depth sizing was 0.63 mm in this work.

Forward Method for Crack Profiles Identification Using Reduced Order Decomposition Techniques Arising in Eddy Current Testing

“…Some successful results of inverse analysis on measurement data of natural crack have been obtained by using ECT inversion application using POD data [27]. Figure 9 illustrates one example from these results.…”

Signal Evaluation System of Flexible Array Ect Probes for Inspecting Complexly Shaped Surfaces

“…Figure 6 schematically explains the 12 decibel down method for estimating flaw edges [3]. ECT has good sensitivity to surface breaks and measurement data are reproducible.…”

“…Flaw length sizing by the 12 decibel down method [3] is effective to find flaw edges in the images. Eddy current paths around the excitation coil greatly affect the phase of the magnetic field.…”

Identification of Crack Profiles using Database and Greedy Search Inverse Analysis Arising in Eddy Current Testing

“…Detail discussion on coil design and measurement parameters are not in the scope of this paper. Based on the ECT measurement method proposed by Nishimizu et al [18], coil and measurement parameters used in this research are described in Table 1. With the measurement parameters described in Table 1, the inversion system proposed in this paper can be applied with measurement data obtained by multi-coil ECT sensors introduced by Nishimizu et al Apparently, using this multi-coil ECT sensors, two different measurement data can be taken into account: Xscan (coils arrangement is perpendicular to scanning direction) and Yscan (as described in Table 1).…”