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.

Defect detection using ultrasonic arrays: The multi-mode total focusing method

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.

Using Deep Learning to Detect Defects in Manufacturing: A Comprehensive Survey and Current Challenges.

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%.

Defect characterization using an ultrasonic array to measure the scattering coefficient matrix

https://hal.archives-ouvertes.fr/hal-01322017/document

Plane Wave Imaging for ultrasonic non-destructive testing: Generalization to multimodal imaging

Sizing of flaws using ultrasonic bulk wave testing: A review

The degree of fatigue in ferritic wrought steel during cyclic bending was determined by analysis of diffracted SH ultrasonic waves with the aid of multiple regression analysis. As the degree of fatigue increases, accompanied by residual stress, the incident waves curve to the interior region with positive stress field owing to the acoustoelastic effect. As a result, the propagation time of the launched waves lengthens, leading to a modulation of the received waveform. Multiple regression analysis for the waveform modulation produces a reliable estimation, with correlation coefficient of 0.948, for the degree of fatigue.

Performance of non-destructive evaluation by diffracted SH ultrasonic waves in predicting degree of fatigue in cyclic bending of ferritic steel

Applicability of AE monitoring technique to evaluate structural integrity of fast breeder reactor piping component

Computerised defect sizing using ALOK analysis in shrunk-on wheel of turbine rotor

A line-current model is proposed to calculate eddy current induced by rectangle coils. Eddy current induced by rectangle coils are analytically calculated using this model, and a coil configuration to induce eddy current deeper into a conductive material is proposed. Optimum excitation frequency is also calculated.

Optimum inducement of eddy current for NDE of deep lying defects: An analytical approach

Japan Nuclear Energy Safety Organization (JNES) has been carrying out the research program entitled “Nondestructive Inspection Technologies for the Cast Stainless Steel Piping” since 2009FY to comprehend the unique ultrasonic wave propagation in the Cast Austenitic Stainless Steel (CASS) and to confirm detection and sizing capability for cracks in the material by currently available ultrasonic testing techniques The research is also intended to provide inspection staff with the fundamental information of ultrasonic wave propagation in CASS, for educational purposeIn this research program, specimens whose material, size, dimension and welding method are identical to the main coolant piping system in Japanese pressurized water reactors (PWRs) are examined Results from the study on the capability for inspection of CASS and the unique wave propagation phenomena such as beam skewing are discussed in this paperCopyright © 2012 by ASME

Ichiro Komura

Papers

Performance of non-destructive evaluation by diffracted SH ultrasonic waves in predicting degree of fatigue in cyclic bending of ferritic steel

Applicability of AE monitoring technique to evaluate structural integrity of fast breeder reactor piping component

Computerised defect sizing using ALOK analysis in shrunk-on wheel of turbine rotor

Optimum inducement of eddy current for NDE of deep lying defects: An analytical approach

Research on Ultrasonic Inspection of Cast Austenitic Stainless Steel Piping