Browse by author
Lookup NU author(s): Hong Zhang,
Dr Bin Gao,
Professor Gui Yun TianORCiD,
Dr Wai Lok Woo,
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Microwave nondestructive testing and evaluation (NDT&E) has tremendous potential for defect detection in metallic materials. In this paper: 1) an open-ended waveguide-based scanning system operating in the X-band (8.2-12.4 GHz) with a spatial-frequency feature extraction algorithm for defect detection at large lift-offs is presented; 2) a full mathematical derivation for modeling the spatial-frequency characteristics in the presence of defects and without defects is provided; and 3) a spatial-frequency feature extraction algorithm using the Itakura-Saito nonnegative matrix factorization is developed and investigated. The algorithm has the unique property of scale-invariance, which enables extraction of spatial-frequency features that are characterized by large dynamic ranges of energy. To evaluate the proposed technique, four defects in an aluminium plate with different depths (from 2 to 8 mm) and one tiny defect on a steel sample (0.45-mm width and 0.43-mm depth) have been examined. Experimental results have demonstrated that the proposed microwave NDT&E technique is capable of detecting defects at large lift-offs, with the potential of estimating the width and depth of defects, as well as classifying the different defect and nondefect areas.
Author(s): Zhang H, Gao B, Tian GY, Woo WL, Simm A
Publication type: Article
Publication status: Published
Journal: IEEE Sensors Journal
Print publication date: 03/02/2014
ISSN (print): 1530-437X
ISSN (electronic): 1558-1748
Altmetrics provided by Altmetric