Crack detection and sizing technique by ultrasonic and electromagnetic methods
TL;DR: In this paper, a 256-channel array system has been developed for the inspection of weldment of BWR internal components such as core shrouds and the TOFD crack sizing technique also can be applied using this system.
About: This article is published in Nuclear Engineering and Design.The article was published on 2001-06-01. It has received 77 citations till now. The article focuses on the topics: Phased array ultrasonics & Phased array.
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TL;DR: In this article, a general imaging methodology, termed multi-mode total focusing method, is proposed in which any combination of modes and reflections can be used to produce an image of the test structure.
Abstract: Ultrasonic arrays allow a given scatterer to be illuminated from a wide range of angles and hence are capable of extracting significant information about the scatterer. In this paper a general imaging methodology, termed multi-mode total focusing method, is proposed in which any combination of modes and reflections can be used to produce an image of the test structure. Like the total focusing method, this approach is implemented by post-processing the full matrix of array data to achieve a synthetic focus at every pixel in the image. A hybrid model is used to predict the array data and demonstrate the performance of the multi-mode imaging concept. This hybrid model combines far field scattering coefficient matrices with a ray-based wave propagation model. This allows the inclusion of longitudinal waves, shear waves and wave mode conversions. It is shown that, with prior knowledge of likely scatterer location and orientation, the mode combination and array location can be optimised to maximise the performance of array inspections. A practically relevant weld inspection application is then described and its optimisation is discussed.
208 citations
TL;DR: In this paper, a survey of state-of-the-art deep learning methods for defect detection is presented, focusing on three aspects, namely method and experimental results, and the core ideas and codes of studies related to high precision, high positioning, rapid detection, small object, complex background, occluded object detection and object association.
Abstract: The detection of product defects is essential in quality control in manufacturing. This study surveys stateoftheart deep-learning methods in defect detection. First, we classify the defects of products, such as electronic components, pipes, welded parts, and textile materials, into categories. Second, recent mainstream techniques and deep-learning methods for defects are reviewed with their characteristics, strengths, and shortcomings described. Third, we summarize and analyze the application of ultrasonic testing, filtering, deep learning, machine vision, and other technologies used for defect detection, by focusing on three aspects, namely method and experimental results. To further understand the difficulties in the field of defect detection, we investigate the functions and characteristics of existing equipment used for defect detection. The core ideas and codes of studies related to high precision, high positioning, rapid detection, small object, complex background, occluded object detection and object association, are summarized. Lastly, we outline the current achievements and limitations of the existing methods, along with the current research challenges, to assist the research community on defect detection in setting a further agenda for future studies.
147 citations
TL;DR: It is demonstrated how measurement of the scattering coefficient matrix of a cracklike defect can be used to obtain its size, shape, and orientation.
Abstract: Ultrasonic nondestructive evaluation is used for detection, characterization, and sizing of defects. The accurate sizing of defects that are of similar or less size than the ultrasonic wavelength is of particular importance in assessing structural integrity. In this paper, we demonstrate how measurement of the scattering coefficient matrix of a cracklike defect can be used to obtain its size, shape, and orientation. The scattering coefficient matrix describes the far field amplitude of scattered signals from a scatterer as a function of incident and scattering angles. A finite element (FE) modeling procedure is described that predicts the scattering coefficient matrix of various cracklike defects. Experimental results are presented using a commercial 64-element, 5 MHz array on 2 aluminum test samples that contain several machined slots and through thickness circular holes. To minimize the interference from the reflections of neighboring defects, a subarray approach is used to focus ultrasound on each target defect in turn and extract its scattering coefficient matrices. A circular hole and a fine slot can be clearly distinguished by their different scattering coefficient matrices over a specific range of incident angles and scattering angles. The orientation angles of slots directly below the array are deduced from the measured scattering coefficient matrix to an accuracy of a few degrees, and their lengths are determined with an error of 10%.
128 citations
Cites background from "Crack detection and sizing techniqu..."
...These defects include fatigue cracks in a solid medium [20], defects in core shroud weldment [21], and defects in thin-walled pipe welds [22]....
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TL;DR: This paper describes a new ultrasonic array imaging method for Non-Destructive Testing (NDT) which is derived from the medical Plane Wave Imaging (PWI) technique, and is compared to the Total Focusing Method (TFM), which is the reference imaging technique in NDT.
114 citations
TL;DR: Techniques that utilise ultrasonic bulk waves to size flaws, including amplitude, temporal, imaging and inversion, are reviewed.
112 citations
References
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TL;DR: In this article, two examples of phased array application were conducted in order to establish the availability of this technique as an actual NDT technique, and it was recognized that both types of scanning mode had the capability for defect detection and successful estimation of the defect size.
11 citations
TL;DR: In this paper, a technique d'essai par ultrason avec reseau en phase peut etre applicable a des centrales nucleaires for le controle electrique du faisceau d'electron and l'affichage image «B scope» en temps reel.
5 citations