Eliminating backwall effects in the phased array imaging of near backwall defects
File(s)
Accepted version
Author(s)
Zhang, Chao
Huthwaite, Peter
Lowe, Michael
Type
Journal Article
Abstract
Ultrasonic array imaging is widely used to provide high quality defect detection and characterization. However, the current imaging techniques are poor at detecting and characterizing defects near a surface facing the array, as the signal scattered from the defect and the strong reflection from the planar backwall will overlap in both time and frequency domains, masking the presence of the defect. To address this problem, this paper explores imaging algorithms and relevant methods to eliminate the strong artefacts caused by the backwall reflection. The half-skip total focusing method (HSTFM), the factorization method (FM) and the time domain sampling method (TDSM) are chosen as the imaging algorithms used in this paper. Then, three methods, referred to as full matrix capture (FMC) subtraction, weighting function filtering, and the truncation method, are developed to eliminate or filter the effects caused by the strong backwall reflection. These methods can be applied easily with few tuning parameters or little prior knowledge. The performances of the proposed imaging techniques are validated in both simulation and experiments, and the results show the effectiveness of the developed methods to eliminate the artefacts caused by the backwall reflections when imaging near backwall defects.
Date Issued
2018-08-29
Date Acceptance
2018-08-01
Citation
Journal of the Acoustical Society of America, 2018, 144 (2), pp.1075-1088
ISSN
0001-4966
Publisher
Acoustical Society of America
Start Page
1075
End Page
1088
Journal / Book Title
Journal of the Acoustical Society of America
Volume
144
Issue
2
Copyright Statement
© 2018 Acoustical Society of America.
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Engineering & Physical Science Research Council (EPSRC)
Engineering and Physical Sciences Research Council
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000443620700058&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
EP/M016315/1
EP/020207/1
EP/M016315/1
Subjects
Science & Technology
Technology
Life Sciences & Biomedicine
Acoustics
Audiology & Speech-Language Pathology
SURFACE-BREAKING CRACKS
NONDESTRUCTIVE EVALUATION
FACTORIZATION METHOD
SCATTERING PROBLEMS
ULTRASONIC ARRAYS
DEPTH MEASUREMENT
SAMPLING METHOD
QUALIFICATION
MATRIX
MEDIA
Publication Status
Published
Date Publish Online
2018-08-29