A novel time reversal sub-group imaging method with noise suppression for damage detection of plate-like structures

Abstract

Summary In this paper, a new time reversal imaging (TRI) algorithm with noise suppression is developed for the application of imaged based structural damage detection of plate‐like structures. The conventional TRI method suffers from performance degradation in high noise condition. The proposed method addresses the aforementioned issues. First, an array of detection transducers is used and is divided into several subgroups. Then, the echo signals of the subgroups are time reversed and reemitted via numerical computation. Finally, the cross‐correlation functions of the summation of refocused time reversed signals in each subgroup are obtained to locate damages. The time reversed signals at the reference time are irrelevant to the noise, meanwhile, the multiple refocused signals in each subgroup are first added and then cross‐correlated. Therefore, the proposed method can effectively suppress noise. To validate the effectiveness of proposed method, 2 experiments were performed. The 2 experiments involved 2 aluminum plate specimens. Each specimen was equipped with 4 surface‐bonded lead zirconate titanate transducers. One specimen involved a simulated damage (an addition of a mass), and the other one involved an actual through‐hole damage. The experimental performances of the proposed method are compared to those of the conventional TRI method. The imaging results demonstrated that the damage on both specimens was clearly displayed with high spatial resolution by the proposed method even under the low signal‐to‐noise ratio condition. On the contrary, the location of the damage computed by the conventional TRI method was submerged in noise and cannot be distinguished.

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“…In the recent years, Lead Zirconate Titanate (PZT) transducers have been widely employed in structural healthy monitoring for the cheapness, stability, and high sensitivity of PZT sensors (Fan et al, 2018; Gao et al, 2018; Xu et al, 2017; Zhang et al, 2018). PZT is a type of piezoceramic material with a strong piezoelectric effect.…”

Advances in the Structural Health Monitoring of Bridges Using Piezoelectric Transducers

“…To suppress the influence of noise on reconstructed images, a time reversal imaging (TRI) algorithm based on noise suppression was proposed by Gao [46]. This method uses the cross-correlation of the time reversal signal as an imaging function to detect the damage of a plate structure.…”

A simplified framework for prediction of sensor network coverage in real-time structural health monitoring of plate-like structures

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