Multi-mode Lamb wave tomography with arrival time sorting
Multi-mode Lamb wave tomography with arrival time sorting
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DOI：
10.1121/1.1867792
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发表时间：
2005-04-01
影响因子：
2.4
通讯作者：
Hinders, MK
中科院分区：
文献类型：
--
作者：
Leonard, KR;Hinders, MK
兰姆波层析成像已被证明是一种有效的板状结构的无损评价技术。超声换能器之间的一系列一发一收测量可以从样品上的不同方向进行，以创建感兴趣的特定特征（如板厚度）的图。大多数以前的工作仅仅依赖于第一到达模式的飞行时间测量和断层重建。这里描述的工作表明兰姆波层析成像系统的能力，从多种模式产生准确的重建。由于每种模式具有不同的厚度方向位移值，因此每种模式对不同类型的缺陷敏感，并且从多模式分析中获得的信息可以提高对被检材料的结构完整性的理解。然而，提取多模到达时间的问题之一是两个模式之间的相消干涉可能导致其中一个模式在信号中似乎消失。在这项工作中提出的排序算法的目标是尝试和抵消这个问题，通过使用多个频率扫描，也被称为频率行走排序的到达时间到正确的模式系列。(c)2005年美国声学学会。
Lamb wave tomography has been shown to be an effective nondestructive evaluation technique for platelike structures. A series of pitch-catch measurements between ultrasonic transducers can be taken from different orientations across the sample to create a map of a particular feature of interest such as plate thickness. Most previous work has relied solely on the first arriving mode for the time-of-flight measurements and tomographic reconstructions. The work described here demonstrates the capability of the Lamb wave tomography system to generate accurate reconstructions from multiple modes. Because each mode has different through-thickness displacement values, each is sensitive to different types of flaws, and the information gained from a multi-mode analysis can improve understanding of the structural integrity of the inspected material. However, one of the problems with the extraction of multi-mode arrival times is that destructive interference between two modes may cause one of the modes to seemingly disappear in the signal. The goal of the sorting algorithm presented in this work is to try and counteract this problem by using multiple frequency scans-also known as frequency walking-to sort the arrival times into their correct mode series. (c) 2005 Acoustical Society of America.