Spiral-shaped piezoelectric sensors for Lamb waves direction of arrival (DoA) estimation

Abstract

A novel strategy to design piezoelectric sensors suited for direction of arrival (DoA) estimation of incoming Lamb waves is presented in this work. The designed sensor is composed by two piezoelectric patches (P1, P2) bonded on the structure to be inspected. In particular, by exploiting the Radon transform, the proposed procedure computes the shape of P2 given the shape of P1 so that the difference in time of arrival (DToA) of the Lamb waves at the two patches is linearly related to the DoA while being agnostic of the waveguide dispersion curves. With a dedicated processing procedure, the waveforms acquired from the two electrodes and digitized can be used to retrieve the DoA information. Numerical and experimental results show that DoA estimation performed by means of the proposed shaped transducers is extremely robust.

Piezoelectric Sensors for Lamb Waves’ Direction of Arrival (DoA) Estimation

“…By exploiting the Propagation of Uncertainty theory, it is possible to observe that, due to the arccos relation, the error in the estimation can be very large for low values of θ . In [2], it was shown that when a linear dependence between the DToA and the DoA is achieved by properly reshaping the sensors so that:…”

“…Then, it is possible to use the cross-correlation method for estimating the DoA. (2). Antitransforming according to Fourier, vP1(t) e vP2(t) are equal except for a scale factor and a linear time-shift in θ , obtaining the desired target: Δt = (ρ0 + αθ )/vg.…”

“…To validate the proposed sensor technology, multiple impacts occurring on an aluminum plate 3 mm of thick were simulated. The response of a shaped piezo-patch to impacts generating the fundamental antisymmetric and symmetric mode (A0 and S0) was computed using the Green's function formalism adopted in [2]. The sensors P1, P2 and P3 are represented in Figure 1a.…”

Application of a Laser-Based Time Reversal Algorithm for Impact Localization in a Stiffened Aluminum Plate

“…To overcome these difficulties, other approaches based on direct strategies and inverse methods have recently been proposed. While the first type requires ad-hoc designed transducers (Salamone et al, 2010;Senesi et al, 2010;Baravelli et al, 2013;De Marchi et al, 2018), the second makes use of a database of responses generated by impacts (Staszewski et al, 2000;Coverley and Staszewski, 2003;Park J. et al, 2009;Ciampa and Meo, 2012). In this context, Park et.…”

Acoustic Emission Source Localization System Using Fiber Bragg Grating Sensors and a Barycentric Coordinate-Based Algorithm

“…AE technique is used to detect, locate, and assess defects. To obtain AE wave, some AE sensors have been widely used, such as piezoelectric sensors (PZT) and capacitive AE sensors [5][6][7][8]. However, the traditional AE sensors have the disadvantages such as complex structure, weak antielectromagnetic interference, and unsuitability for distributed measurement.…”