Hongjuan Yan

TL;DR: In this paper, an acoustic surface wave high-order nonlinear parameter representation method for a bending fatigue state of a metal plate is used for detecting the bending fatigue states of the metal plate in real-time and predicting the residual bending fatigue life.

TL;DR: In this article, a modified S-transform domain singular value decomposition method for the analysis of ultrasonic flaw echo signals is presented. And the authors try to decompose the singular entropy of effective echo signal and realize the adaptive filter, which can not only remove high frequency noise but also remove the low frequency noise and improve the signal-to-noise ratio of echo signal.

TL;DR: In this article, the nonlinear ultrasonic testing system is used to detect received signals during tensile testing and bending fatigue testing of GH4169 superalloy, and the results show that the curves of nonlinear Ultrasonic parameters as a function of tensile stress or fatigue life are approximately saddle.

TL;DR: A method for ultrasonic thickness measurement of coatings by Welch power spectrum is described in this article, where the multiple reflections of ultrasonic waves in coating layer lead to a series of maximum energy occurred in the Welch spectrum, which can be implemented to evaluate the thickness of coating.

Abstract: 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.