A methodology for structural health monitoring with diffuse ultrasonic waves in the presence of temperature variations
A methodology for structural health monitoring with diffuse ultrasonic waves in the presence of temperature variations
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DOI：
10.1016/j.ultras.2005.05.001
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发表时间：
2005-10-01
期刊：
影响因子：
4.2
通讯作者：
Michaels, JE
中科院分区：
文献类型：
--
作者：
Lu, YH;Michaels, JE
用于结构健康监测的漫射超声波提供了信号产生和接收简单、对损伤敏感和大面积覆盖的优点;然而，没有被接受的方法来分析复杂的记录信号和对环境变化（例如温度和表面条件）敏感的严重缺点。本文提出了一种将漫射超声波应用于检测存在不可测温度变化的结构损伤的方法。该方法基于温度变化对扩散超声波的一阶效应是时间膨胀或压缩的预测和观察。实施多步骤程序，以（1）在跨越预期操作范围的温度下记录来自未损坏试样的一组基线波形，（2）选择波形。从其温度最接近随后测量的信号的温度的基线组，（3）调整该基线波形以最佳地匹配信号，以及（4）计算信号和调整后的波形之间的误差参数，并将该参数与阈值进行比较以确定结构状态。这个过程适用于铝板试件与人工缺陷的实验数据。检测概率和检测到的最小缺陷尺寸作为基线波形集的大小的函数。它示出了超过95%的检测概率可以实现与少量的基线波形。(c)2005 Elsevier B. V.保留所有权利。
Diffuse ultrasonic waves for structural health monitoring offer the advantages of simplicity of signal generation and reception, sensitivity to damage, and large area coverage; however, there are the serious disadvantages of no accepted methodology for analyzing the complex recorded signals and sensitivity to environmental changes such as temperature and surface conditions. Presented here is a methodology for applying diffuse ultrasonic waves to the problem of detecting structural damage in the presence of unmeasured temperature changes. This methodology is based upon the prediction and observation that the first order effect of a temperature change on a diffuse ultrasonic wave is a time dilation or compression. A multi-step procedure is implemented to (1) record a set of baseline waveforms from the undamaged specimen at temperatures spanning the expected operating range, (2) select a waveform. from the baseline set whose temperature is the closest to that of a subsequently measured signal, (3) adjust this baseline waveform to best match the signal, and (4) calculate an error parameter between the signal and the adjusted waveform and compare this parameter to a threshold to determine the structural status. This procedure is applied to experimental data from aluminum plate specimens with artificial flaws. Probability of detection and the minimum flaw size detected are presented as a function of the size of the baseline waveform set. It is shown that a probability of detection of over 95% can be achieved with a small number of baseline waveforms. (c) 2005 Elsevier B.V. All rights reserved.