Time reversal technique for health monitoring of metallic structure using Lamb waves
Time reversal technique for health monitoring of metallic structure using Lamb waves
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DOI：
10.1016/j.ultras.2009.05.002
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发表时间：
2009-12-01
期刊：
影响因子：
4.2
通讯作者：
Bhat, M. R.
中科院分区：
文献类型：
--
作者：
Gangadharan, R.;Murthy, C. R. L.;Bhat, M. R.
研究了使用兰姆波的时间反转主动传感来对金属结构进行健康监测。在铝板上进行了实验，研究了窄带和宽带脉冲激励下A(0)和S-0兰姆波模式的时间反转行为。在板中引入缺口形式的损伤，通过实验研究时间反转兰姆波模式的特性变化。对时间反演信号进行时频分析，提取损伤信息。推导了基于小波变换的损伤度量，以量化时间反转信号中隐藏的损伤信息。研究表明，时间反转可用于在宽带信号激励下实现兰姆波的时间再压缩。此外，宽带激励还可以提高该技术检测紧密定位缺陷的分辨率。这可以通过拾取来自板边缘、靠近板边缘的缺陷以及彼此靠近的缺陷的波反射来证明。这项研究展示了兰姆波时间反转对色散兰姆波时间再压缩在健康监测应用中进行损伤检测的有效性。 (C) 2009 Elsevier B.V. 保留所有权利。
Time reversal active sensing using Lamb waves is investigated for health monitoring of a metallic structure. Experiments were conducted on an aluminum plate to study the time reversal behavior of A(0) and S-0 Lamb wave modes under narrow band and broad band pulse excitation. Damage in the form of a notch was introduced in the plate to study the changes in the characteristics of the time reversed Lamb wave modes experimentally. Time-frequency analysis of the time reversed signal was carried out to extract the damage information. A measure of damage based on wavelet transform was derived to quantify the hidden damage information in the time reversed signal. It has been shown that time reversal can be used to achieve temporal recompression of Lamb waves under broadband signal excitation. Further, the broad band excitation can also improve the resolution of the technique in detecting closely located defects. This is demonstrated by picking up the reflection of waves from the edge of the plate, from a defect close to the edge of the plate and from defects located near to each other. This study shows the effectiveness of Lamb wave time reversal for temporal recompression of dispersive Lamb waves for damage detection in health monitoring applications. (C) 2009 Elsevier B.V. All rights reserved.