Fan beam and double crosshole Lamb wave tomography for mapping flaws in aging aircraft structures
Fan beam and double crosshole Lamb wave tomography for mapping flaws in aging aircraft structures
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DOI：
10.1121/1.1289663
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发表时间：
2000-10-01
影响因子：
2.4
通讯作者：
Hinders, MK
中科院分区：
文献类型：
--
作者：
Malyarenko, EV;Hinders, MK
随着全球航空机队继续老化，准确预测是否存在危及适航性的结构缺陷--如隐藏的腐蚀和剥离--的方法变得越来越必要。超声导波，兰姆波，允许快速检查飞机结构的大段。然而，从兰姆波数据中提取定量信息总是需要训练有素、具有详细机械波导物理知识的人员参与。本文总结的工作集中在各种不同的层析重建技术，以图形化地表示兰姆波数据在定量地图上，技术人员可以很容易地解释。例如，因为兰姆波的速度取决于厚度，所以可以将基本兰姆波的传播时间转换成检查区域的厚度图。这篇文章描述了兰姆波层析成像技术的两种潜在的实用实现，这两种技术可以优化用于大面积飞机结构的现场测试。本文讨论的实验室测量表明，使用扇束重建的环形换能器或代数重建的正方形换能器阵列的兰姆波层析成像适合于检测多层飞机材料的缺陷。本文讨论了重建算法的速度和保真度以及基于个人便携阵列的系统的实用考虑。(C)2000年美国声学学会。[S0001-4966(00)02110-X]。
As the worldwide aviation fleet continues to age, methods for accurately predicting the presence of structural flaws-such as hidden corrosion and disbonds-that compromise airworthiness become increasingly necessary. Ultrasonic guided waves, Lamb waves, allow large sections of aircraft structures to be rapidly inspected. However, extracting quantitative information from Lamb wave data has always involved highly trained personnel with a detailed knowledge of mechanical waveguide physics. The work summarized here focuses on a variety of different tomographic reconstruction techniques to graphically represent the Lamb wave data in quantitative maps that can be easily interpreted by technicians. Because the velocity of Lamb waves depends on thickness, for example, the traveltimes of the fundamental Lamb modes can be converted into a thickness map of the inspection region. This article describes two potentially practical implementations of Lamb wave tomographic imaging techniques that can be optimized for in-the-field testing of large-area aircraft structures. Laboratory measurements discussed here demonstrate that Lamb wave tomography using either a ring of transducers with fan beam reconstructions, or a square array of transducers with algebraic reconstruction tomography, is appropriate for detecting flaws in multilayer aircraft materials. The speed and fidelity of the reconstruction algorithms as well as practical considerations for person-portable array-based systems are discussed in this article. (C) 2000 Acoustical Society of America. [S0001-4966(00)02110-X].