Title Development of a 2D analytical model for the prediction of directivity pattern of transducers in the generation of guided wave modes /
Authors Tiwari, Kumar Anubhav ; Raisutis, Renaldas ; Mazeika, Liudas ; Samaitis, Vykintas
DOI 10.1016/j.prostr.2017.07.139
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Is Part of Procedia structural integrity: 2nd international conference on structural integrity, ICSI 2017: 4-7 September 2017, Funchal, Madeira, Portugal / edited by: F. Iacoviello, P.M.G.P. Moreira and P.J.S. Tavares.. Amsterdam : Elsevier. 2017, vol. 5, p. 973-980.. ISSN 2452-3216
Keywords [eng] analytical model ; directivity ; Macro fiber Composite (MFC) ; lamb mode ; shear horizontal ; ultrasonic NDT ; transducer
Abstract [eng] The guided waves (GW) are extensively used in the nondestructive testing (NDT) and structure health monitoring (SHM) of the large and complex structures. It enables to detect the defects up to few meters away from the transducers. However, the defects could occur at longer distances. In order to cover the test area of interest for the estimation of defects and to find the exact position of the transducers to be glued/ embedded, the directivity pattern of the transducers must be known. The aim of the presented work is to develop the 2D analytical model for the estimation of directivity patterns of the transducers at various frequencies and distances. The model was developed using the Huygens's principle of wave propagation distances with considering the known phase dispersive characteristics of the guided wave modes in the medium. The principle of modelling will work to plot the directivity pattern at any distance, at any excitation frequency and with any configuration and shape of the transducers. In order to demonstrate the model, the directivity patterns of P1-type macro-fiber composite (MFC) transducer in the generation of fundamental Lamb modes and shear horizontal mode at 300 mm from the center of MFC were obtained. The input signal used was 80 kHz, 3 period signal and propagation medium was Al plate of 2 mm thickness. The prediction about the position of where MFC transducer should be placed or glued on the object and selection of proper wave modes in order to estimate the defects in various materials is also discussed. The results were validated using finite element analysis (FEA) performed in ANSYS and further verified by the experimental analysis using low-frequency (LF) ultrasonic measurement system ULTRALAB, developed by Ultrasound Research Institute, Kaunas University of Technology. The proposed analytical model will not only facilitate to decide the position and number of transducers but also leads to choosing the configuration of transducer and wave modes suitable to be used for the inspection of defects.
Published Amsterdam : Elsevier
Type Conference paper
Language English
Publication date 2017
CC license CC license description