An improved two-dimensional multiple signal classification approach for impact localization on a composite structure

Abstract

Efficient impact monitoring techniques are important to be researched to ensure the safety of in-service composite structures. Multiple signal classification-based method is a new promising method. This method uses small aperture sensor array arrangement instead of sparse sensor arrangement. It has the advantage of easy sensor array arrangement. By processing the whole sensor array outputs using the multiple signal classification algorithm, transfer function and material property of the structure are not needed. Although some researches have shown the potential of this new method, most of the current researches have been performed based on the far-field assumption on aluminum structures. In engineering applications, composite structures are the main structures which need impact monitoring. Deep research needs to be addressed. Aiming at these problems, an improved two-dimensional near-field multiple signal classification processing algorithm is presented for impact localization on composite structure in this article. The proposed method can simultaneously estimate the impact occurring direction and distance. A uniform carbon fiber composite plate and a real aircraft oil tank made of carbon composite structure with varied thickness are adopted to evaluate the presented method. To deal with the anisotropy performance of the complex composite, the two-dimensional multiple signal classification processing algorithm is also improved by taking into account the existing anisotropy performance.

Imaging damage in plate waveguides using frequency-domain multiple signal classification (F-MUSIC)

“…The conventional MUSIC algorithm [3,21,29] is recalled to image the same damage in the above scenario for comparison. To this end, seven PZT wafers are configured in a linear array as wave receivers, Fig.…”

Focusing phase imaging for Lamb wave phased array

“…Although the phase consistency index CI (t f ) is high at this situation, it does not mean that the point is damaged. Therefore, in order to measure the degree of alignment between the instantaneous phase and the zero phase, the average of phases is taken into consideration, and the alignment index of the instantaneous phases is established as shown in equation (13):…”

“…In essence, the DOA estimation is based on the phase difference among the receivers. Yuan's group [12][13][14][15][16] extended the conventional MUSIC from the far-field hypothesis to near-field situation and developed several revamped MUSIC-based algorithms. Yang et al [17] ameliorated the MUSIC with a sparse array.…”

Forward-propagation-free focusing MUSIC algorithm for Lamb waves

“…Engholm and Stepinski 31 estimated the DOA of a transmitter source on an aluminum plate with a uniform circular array using Lamb waves. Zhong et al 32 extended the MUSIC from the far-field assumption to near-field situation and presented a 2D MUSIC to estimate the direction and distance of the impact using Lamb waves. And a correlated near-field MUSIC is also proposed by Zhong et al 33 to distinguish multiple correlated defects by utilizing the spatial smoothing technique.…”