Structural Damage Iterative Focusing Imaging Monitoring Method Based on Synthetic Time Inversion

Abstract

The invention discloses a structural damage iterative focusing imaging monitoring method based on synthetic time-reversal. The method includes: performing N×S times of independent single-channel excitation-single-channel reception on a physical structure that needs to be synchronously detected by an N-S array Active stress wave detection; linearly superimpose the N-channel received signals of each unit in the S-array to obtain the S-channel composite signal; perform time inversion and amplification of the S-channel composite signal, and perform N×S independent single-channel excitation on the physical structure-single channel Received time-reversal detection; linearly superimpose the S-channel received signals of each unit in the N array to obtain N-channel synthetic time-reverse signals; use the synthetic time-reverse to continue iterative detection of the physical structure, and finally obtain N-channel synthetic iterative signals; Based on the time-reversal imaging method of time-domain focusing, the synthesized iterative signals are time-reversed and amplified, and each N-array unit of the imaging model is stimulated and transmitted back to realize focused damage imaging.

Description

technical field [0001] The invention relates to the field of testing and measurement technology and structural health monitoring, in particular to a method for monitoring structural damage iterative focusing imaging based on synthetic time inversion. Background technique [0002] Time reversal refers to a reverse order processing of the measured time domain signal, which reverses the measured signal back and forth according to the order in which it arrives at the receiving point. According to the principle of reciprocity, time inversion has the characteristic of time-space focusing, which is specifically reflected in the following: after time-reversal processing of received signals from damaged targets measured at multiple points in space, the obtained multi-channel time-reversal signals can be obtained without prior knowledge , Adaptively pass through the complex medium to superimpose the maximum energy at the spatial damage target at the same time, and form a focusing sign...

AI Technical Summary

Problems solved by technology

[0003] According to the above analysis, if the traditional time-reversal mirror imaging method is used in actual detection, it is necessary to design synchronous excitation and synchronous acquisition devices for multiple transmitting array units and receiving array units, which requires extremely high performance of hardware equipment; in addition, the traditional time The accuracy of the mirror imaging algorithm is also limited by factors such as the number of receiving array units, propagation path loss, and multiple damaged targets.

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