Fast damage imaging using the time-reversal technique in the frequency–wavenumber domain

Abstract

The time-reversal technique has been successfully used in structural health monitoring (SHM) for quantitative imaging of damage. However, the technique is very time-consuming when it is implemented in the time domain. In this paper, we study the technique in the frequency-wavenumber (f-k) domain for fast real-time imaging of multiple damage sites in plates using scattered flexural plate waves. Based on Mindlin plate theory, the time reversibility of dispersive flexural waves in an isotropic plate is theoretically investigated in the f-k domain. A fast damage imaging technique is developed by using the cross-correlation between the back-propagated scattered wavefield and the incident wavefield in the frequency domain. Numerical simulations demonstrate that the proposed technique cannot only localize multiple damage sites but also potentially identify their sizes. Moreover, the time-reversal technique in the f-k domain is about two orders of magnitude faster than the method in the time domain. Finally, experimental testing of an on-line SHM system with a sparse piezoelectric sensor array is conducted for fast multiple damage identification using the proposed technique.

Damage Assessment in Metal Plates by Using Laser Vibrometer Measurements

“…The filtered wavefield u W (t, x) can severe as the input data of the array beamforming technique for damage detection. In this study, the array beamforming algorithm is based on the phase delay-and-sum beamforming [6] and reversed wavefield construction [5,14,15]. The array beamforming algorithm can be summarized as,…”

An Aircraft Pallet Damage Monitoring Method Based on Damage Subarea Identification and Probability-Based Diagnostic Imaging

“…Among the existing researches of SHM technology based on Lamb wave and piezoelectric transducer, damage imaging algorithm is an easily interpretable and intuitive image re ecting the overall health status of the monitored structure, which has been widely studied [24,25], such as the delay-and-sum imaging method [26][27][28][29][30], ultrasonic phased array imaging method [31][32][33][34], time reversal imaging method [35][36][37][38][39], multiple signal classi cation method [40][41][42][43] and spatial-wavenumber lter imaging method [44][45][46][47]. Lu et al improved the delay-and-sum imaging method by employing the Boolean ADD operation instead of the addition or the multiplication operation, and used re ection coe cient, local maximum value based envelop-detection method, additional time shi to cancel the artifacts and increase the e cient and accuracy of defect detection [48].…”

“…Yu et al combine ultrasonic phased array imaging method and spatial-wavenumber lter to detect and quantify impact induced delamination damage in composites, which is reduced the total composite inspection time by 97% compared to the full scanning laser Doppler vibrometer approach [49,50]. Zhu et al studied the time reversal imaging method in frequency-wavenumber domain for multiple damage imaging, which is about two orders of magnitude faster than that in the time domain [51]. e present studies show that these methods require knowledge of the Lamb wave velocity in the damage location.…”

Impact imaging of aircraft composite structure based on a model-independent spatial-wavenumber filter

“…In the past decade, Lamb wave based structural damage imaging methods have been studied widely and show a good application potential [9][10][11][12][13][14][15][16][17][18][19]. Therefore, several researchers began to introduce structural imaging methods to impact localization in recent years.…”