Barzegar Mohsen, Pasadas Dario Jeronimo, Lopes Ribeiro Artur, Ramos Helena Geirinhas
IEEE Trans Ultrason Ferroelectr Freq Control. 2022 Jun;69(6):2143-2151. doi: 10.1109/TUFFC.2022.3164731. Epub 2022 May 26.
In this study, dispersion curve estimation of a bonded aluminum plate is carried out by proposing a specific signal processing procedure. In this proposed method, the angle beam ultrasonic transducer measurement system in a pitch-catch configuration is used to acquire Lamb wave signals from two adjacent positions. The obtained signals are processed then by using signal processing techniques, including bandpass filters, fast Fourier transform (FFT), and bandpass Gaussian filters. Various transmitted signals with different central frequencies are used to estimate four modes of the utilized bonded specimen for frequencies less than 1 MHz. The dispersion curve results in terms of phase velocity and wavenumbers are compared with theoretical dispersion curves and 2-D FFT. This comparison is carried out by using three different metrics, which shows the maximum mean relative error of 3.46% with low variance.
在本研究中，通过提出一种特定的信号处理程序来进行粘结铝板的频散曲线估计。在该方法中，采用了一发一收配置的斜探头超声换能器测量系统，从两个相邻位置采集兰姆波信号。然后使用包括带通滤波器、快速傅里叶变换（FFT）和带通高斯滤波器在内的信号处理技术对所获得的信号进行处理。对于频率低于1MHz的情况，使用具有不同中心频率的各种发射信号来估计所用粘结试件的四种模式。将相速度和波数方面的频散曲线结果与理论频散曲线和二维FFT进行比较。这种比较是通过使用三种不同的指标进行的，结果显示最大平均相对误差为3.46%，方差较小。
