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.
Articles you may be interested inDevelopment of flexible array eddy current probes for complex geometries and inspection of magnetic parts using magnetic sensors AIP Conf.ABSTRACT. We developed a signal evaluation system of flexible array eddy current testing (ECT) probes for inspecting complexly shaped metal surfaces. Our probes employ excitation and pickup coil pairs arrayed on a bendable substrate to measure curved targets. Since the developed probes produce signals due to the change in the relative position between the coil pair, an evaluation module for flaw signal identification is integrated into the system. The identification utilizes signal phase combination of the coil pairs. It is represented as a two-dimensional diagram constituting the phase values of two of the coil pairs with different positions. The phase of signals around flaws is significantly affected by their orientations. The diagram is therefore capable of separating flaw information from other information and of imaging flaw positions. We applied the system to complex geometric mock-ups. Flaw signals were successfully identified and the images obtained for identified positions could be used to efficiently measure the length of surface flaws by the 12 decibel down method.
Non-destructive inspection (NDI) is used to detect defects for safety. The magneto optical (MO) imaging is an attractive method for NDI. The MO imaging can visualize defects as a light intensity of image, which depends on the polarization rotation angle of the MO film. The polarization rotation angle depends on the stray filed in the vertical direction. To accurately detect the stray field, it is necessary to enhance the Faraday rotation angle. Therefore, we focused on magnetophotonic crystal (MPC), which can enhance the MO effect with thin film, comprising the polycrystalline bismuth substituted yttrium iron garnet. We estimated the defect depth with the MPC located on the iron with a defect, which depth was varied from 1 mm to 10 mm. The results showed good agreement with the defect depth measured by the dial gauge.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.