A Local TR-MUSIC Algorithm for Damage Imaging of Aircraft Structures

Abstract

Lamb wave-based damage imaging is a promising technique for aircraft structural health monitoring, as enhancing the resolution of damage detection is a persistent challenge. In this paper, a damage imaging technique based on the Time Reversal-MUltiple SIgnal Classification (TR-MUSIC) algorithm is developed to detect damage in plate-type structures. In the TR-MUSIC algorithm, a transfer matrix is first established by exciting and sensing signals. A TR operator is constructed for eigenvalue decomposition to divide the data space into signal and noise subspaces. The structural space spectrum of the algorithm is calculated based on the orthogonality of the two subspaces. A local TR-MUSIC algorithm is proposed to enhance the image quality of multiple damages by using a moving time window to establish the local space spectrum at different times or different distances. The multidamage detection capability of the proposed enhanced TR-MUSIC algorithm is verified by simulations and experiments. The results reveal that the local TR-MUSIC algorithm can not only effectively detect multiple damages in plate-type structures with good image quality but also has a superresolution ability for detecting damage with distances smaller than half the wavelength.

A Review of Laser Ultrasonic Lamb Wave Damage Detection Methods for Thin-Walled Structures

“…Time reversal with the MUSIC (TR-MUSIC) and decomposition of the time reversal operator (DORT) are typical subspace class algorithms, both of which use noise subspace and signal subspace to construct the space spectrum, respectively. Yun et al [ 99 ] built a detection system for PL-PZT and proposed the modified TR–MUSIC, which uses moving time windows to establish the local spatial spectrum at different times and distances, so as to improve the image quality of multiple damages. However, the distance resolution is very low.…”

Lightning Localization Using Three-Dimensional Time Reversal MUltiple SIgnal Classification (TR-MUSIC) Algorithm

“…In this paper, we propose for the first time an approach based on the Time Reversal (TR)-MUSIC algorithm for a 3D, high resolution imaging of the lightning channel. The TR-MUSIC method combines the super-resolution property of the MUSIC algorithm with the adaptive focusing of the EMTR method [16], [17].…”

Fatigue Crack Propagation Monitoring Using Fibre Bragg Grating Sensors

“…Examples of such algorithms are: multiple signal classification (MUSIC) and the reconstruction algorithm for probabilistic inspection of damage (RAPID). MUSIC is a method used to address the Rayleigh criterion [27] and has been applied to a variety of guided wave-based SHM systems. Zhong et al [28] applied the MUSIC algorithm to distinguish multiple damage on a carbon-fibre-reinforced polymer (CFRP) plate and a real aircraft composite oil tank.…”

“…Zhong et al [28] applied the MUSIC algorithm to distinguish multiple damage on a carbon-fibre-reinforced polymer (CFRP) plate and a real aircraft composite oil tank. Fan et al [27] proposed a modification of MUSIC, combining the adaptive focusing of the time reversal algorithm and the high resolution of direction estimation of the MUSIC algorithm. The modified MUSIC algorithm was applied for the SHM system based on Lamb waves for damage (drilled holes) detection in aluminium plate-type aircraft structures [27].…”

“…Fan et al [27] proposed a modification of MUSIC, combining the adaptive focusing of the time reversal algorithm and the high resolution of direction estimation of the MUSIC algorithm. The modified MUSIC algorithm was applied for the SHM system based on Lamb waves for damage (drilled holes) detection in aluminium plate-type aircraft structures [27]. Bao et al [29] proposed another modification to the MUSIC algorithm that overcomes the problems related to the low signal-to-noise ratio (SNR) of damage scattered signals, as well as the structural anisotropy in complex elements that limits the localisation ability of the algorithm.…”