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Lamb波技术非常适于板类结构的各种缺陷检测。为了得到模态较为单一的Lamb波,使得接收信号更具有解释性,缺陷更容易识别,该文中在板上下表面的相同位置分别布置压电传感器阵列,采用同一位置上下表面的双压电片同相或反相激励,激励出单一S0或A0模态。运用这种单模态的Lamb波激励方式对板中缺陷进行检测,结合椭圆成像算法与数据融合方法对压电传感器阵列接收到的多组信号进行缺陷成像。该方法有效的实现了板中缺陷的二维成像定位,检测出人工缺陷,并提高了缺陷的可识别能力和定位精度。
Lamb wave technology is ideal for a variety of defect detection board structure. In order to obtain a more mode-specific Lamb wave, the received signal is more explanatory and the defects are easier to identify. In this paper, the piezoelectric sensor array is arranged at the same position on the upper and the lower surfaces of the board, Or inverting excitation to excite a single S0 or A0 mode. The single-mode Lamb wave excitation method is used to detect the defects in the plate. Combined with the ellipse imaging algorithm and the data fusion method, multiple sets of signals received by the piezoelectric sensor array are subjected to defect imaging. The method effectively realizes the two-dimensional imaging and positioning of the defects in the plate, detects the artificial defects, and improves the recognizability and the positioning accuracy of the defects.