Defect detection of curved thin shell based on ultrasonic transducer array

The curved spherical thin shell structures are widely used in the practical industrial applications, because of the defects in it, a lot of major accidents occurred and caused significant economic losses. So monitoring and quantifying the defects in curved plate structure are studied here. On the basis of the fundamental theory of the guide wave that propagating in the curved thin shell, and by solving and analysing the guide wave's dispersion, the guide wave's inspiring method has been obtained from the wave-mode conversion. The ellipse localisation imaging algorithm is applied to identify the defect's orientation and localisation accurately. Wavelet transform is used to obtain the defect's location parameters. A series of experiments for detecting the artificial defect at the specimen have shown that the defect's direction and location can be detected effectively.