3D ultrasonic imaging of surface-breaking cracks using a linear array

Ultrasonic linear arrays have great potential to generate high-quality three-dimensional (3D) images by scanning the array. However, the generated images suffer from low resolution in the elevation plane, limiting the image quality for a reliable 3D Non-Destructive Testing (NDT) inspection. Although...

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Main Authors: Saini, Abhishek, Lane, Christopher J. L., Tu, Juan, Xue, Honghui, Fan, Zheng
Other Authors: School of Mechanical and Aerospace Engineering
Format: Article
Language:English
Published: 2022
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Online Access:https://hdl.handle.net/10356/163327
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1633272022-12-02T05:44:06Z 3D ultrasonic imaging of surface-breaking cracks using a linear array Saini, Abhishek Lane, Christopher J. L. Tu, Juan Xue, Honghui Fan, Zheng School of Mechanical and Aerospace Engineering Engineering::Mechanical engineering Phased Array Resolution 3D Imaging Ultrasonic linear arrays have great potential to generate high-quality three-dimensional (3D) images by scanning the array. However, the generated images suffer from low resolution in the elevation plane, limiting the image quality for a reliable 3D Non-Destructive Testing (NDT) inspection. Although several ultrasonic imaging methods have been implemented to inspect different types of defects, there has been limited research to characterise surface-breaking cracks (SBCs) in 3D quantitatively. To improve the characterisation of surface-breaking cracks (SBCs), a 3D hybrid imaging method is proposed by combining the Half Skip Total Focusing Method (HSTFM) and the Synthetic Aperture Focusing Technique (SAFT) using a linear array. This paper proposed the implementation of an array with a reduced element length for full matrix capture (FMC) data acquisition. In conjunction with the hybrid imaging method, a reduced element array enables the utilisation of the information from a broad ultrasonic beam in the elevation direction to achieve improved image resolution. The imaging capability is assessed via a point spread function (PSF) as well as numerical simulations. From the PSF measurements, the image resolution is shown to improve with the smaller element length of the array, which is attributable to the combination of wide beamwidth and hybrid imaging method. Thereafter, experimental validation was performed with arrays of different elevation lengths, where an excellent match with the numerical results was observed. Furthermore, the crack sizing was performed using a 6-dB-drop rule, which assisted in accurately predicting the shape and size of the SBCs and is shown to measure the depth of SBCs with greater confidence. It is shown that a reduced array elevation with the hybrid imaging method and sizing method yields improved image resolution contrary to conventional linear arrays. This approach can offer a significant improvement in manifesting complete comprehension of the spatial defect relationship, enabling NDT engineers to analyse the inspection results quantitatively in 3D for progressive reliability. Agency for Science, Technology and Research (A*STAR) This work was financially supported by A*STAR Science and Engineering Research Council under AME Individual Research Grant (IRG) 2018 Grant Call (Project No. A1983c0030). 2022-12-02T05:44:06Z 2022-12-02T05:44:06Z 2022 Journal Article Saini, A., Lane, C. J. L., Tu, J., Xue, H. & Fan, Z. (2022). 3D ultrasonic imaging of surface-breaking cracks using a linear array. Ultrasonics, 125, 106790-. https://dx.doi.org/10.1016/j.ultras.2022.106790 0041-624X https://hdl.handle.net/10356/163327 10.1016/j.ultras.2022.106790 35835009 2-s2.0-85133671218 125 106790 en A1983c0030 Ultrasonics © 2022 Elsevier B.V. All rights reserved.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Mechanical engineering
Phased Array Resolution
3D Imaging
spellingShingle Engineering::Mechanical engineering
Phased Array Resolution
3D Imaging
Saini, Abhishek
Lane, Christopher J. L.
Tu, Juan
Xue, Honghui
Fan, Zheng
3D ultrasonic imaging of surface-breaking cracks using a linear array
description Ultrasonic linear arrays have great potential to generate high-quality three-dimensional (3D) images by scanning the array. However, the generated images suffer from low resolution in the elevation plane, limiting the image quality for a reliable 3D Non-Destructive Testing (NDT) inspection. Although several ultrasonic imaging methods have been implemented to inspect different types of defects, there has been limited research to characterise surface-breaking cracks (SBCs) in 3D quantitatively. To improve the characterisation of surface-breaking cracks (SBCs), a 3D hybrid imaging method is proposed by combining the Half Skip Total Focusing Method (HSTFM) and the Synthetic Aperture Focusing Technique (SAFT) using a linear array. This paper proposed the implementation of an array with a reduced element length for full matrix capture (FMC) data acquisition. In conjunction with the hybrid imaging method, a reduced element array enables the utilisation of the information from a broad ultrasonic beam in the elevation direction to achieve improved image resolution. The imaging capability is assessed via a point spread function (PSF) as well as numerical simulations. From the PSF measurements, the image resolution is shown to improve with the smaller element length of the array, which is attributable to the combination of wide beamwidth and hybrid imaging method. Thereafter, experimental validation was performed with arrays of different elevation lengths, where an excellent match with the numerical results was observed. Furthermore, the crack sizing was performed using a 6-dB-drop rule, which assisted in accurately predicting the shape and size of the SBCs and is shown to measure the depth of SBCs with greater confidence. It is shown that a reduced array elevation with the hybrid imaging method and sizing method yields improved image resolution contrary to conventional linear arrays. This approach can offer a significant improvement in manifesting complete comprehension of the spatial defect relationship, enabling NDT engineers to analyse the inspection results quantitatively in 3D for progressive reliability.
author2 School of Mechanical and Aerospace Engineering
author_facet School of Mechanical and Aerospace Engineering
Saini, Abhishek
Lane, Christopher J. L.
Tu, Juan
Xue, Honghui
Fan, Zheng
format Article
author Saini, Abhishek
Lane, Christopher J. L.
Tu, Juan
Xue, Honghui
Fan, Zheng
author_sort Saini, Abhishek
title 3D ultrasonic imaging of surface-breaking cracks using a linear array
title_short 3D ultrasonic imaging of surface-breaking cracks using a linear array
title_full 3D ultrasonic imaging of surface-breaking cracks using a linear array
title_fullStr 3D ultrasonic imaging of surface-breaking cracks using a linear array
title_full_unstemmed 3D ultrasonic imaging of surface-breaking cracks using a linear array
title_sort 3d ultrasonic imaging of surface-breaking cracks using a linear array
publishDate 2022
url https://hdl.handle.net/10356/163327
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