Structural imaging through local wavenumber estimation of guided waves
Structural imaging through local wavenumber estimation of guided waves
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DOI：
10.1016/j.ndteint.2013.04.003
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发表时间：
2013-10-01
影响因子：
4.2
通讯作者：
Lee, Jung-Ryul
中科院分区：
文献类型：
--
作者：
Flynn, Eric B.;Chong, See Yenn;Lee, Jung-Ryul
本文描述了一种通过在空间采样点的细网格处对传播的引导兰姆波的波数进行局部估计来有效地对结构特征和缺陷进行成像的方法。导波在每个网格点处使用扫描Q开关激光系统快速激发，并由单个固定的超声换能器感测。通过互易性，这产生从换能器激发的虚拟波的全波场时间历程。使用频率波数处理，通过隔离每个波模式、对一个或多个高能量频带进行窄带滤波以及识别使每个网格点处的能量最大化的滑动波数带通滤波器的中心波长来获得局部波长估计。该方法能够产生详细的图像隐藏的壁变薄的铝板和钢管节和局部冲击分层在一个复杂的复合材料部件。(C)2013爱思唯尔有限公司保留所有权利。
This paper describes a method to effectively image structural features and defects using local estimates of the wavenumber of propagating guided Lamb waves at a fine grid of spatial sampling points. The guided waves are rapidly excited at each grid point using a scanning Q-switched laser system and sensed by a single fixed ultrasonic transducer. Through reciprocity, this produces a full-wave-field time history of a virtual wave being excited from the transducer. Using frequency wavenumber processing, localized wavelength estimates are obtained by isolating each wave mode, narrowband filtering to one or more high-energy frequency bands, and identifying the center-wavelength of a sliding wavenumber band-pass filter that maximizes the energy at each grid point. The approach was capable of producing detailed images of hidden wall-thinning in an aluminum plate and a steel pipe section and local impact delamination in a complicated composite component. (C) 2013 Elsevier Ltd. All rights reserved.