An investigation into the temperature stability of a guided wave structural health monitoring system using permanently attached sensors
An investigation into the temperature stability of a guided wave structural health monitoring system using permanently attached sensors
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DOI：
10.1109/jsen.2007.894908
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发表时间：
2007-05-01
影响因子：
4.3
通讯作者：
Drinkwater, Bruce W.
中科院分区：
文献类型：
--
作者：
Konstantinidis, Georgios;Wilcox, Paul D.;Drinkwater, Bruce W.
当使用可展开导波系统测试复杂结构时，所测量的信号通常太复杂而不能在没有结构几何形状的先验知识的情况下直接解释。然而，在结构健康监测（SHM）场景中，传感器永久地附接到结构，因此可以通过与结构未受损时进行的早期基线测量进行比较来监测系统中的变化。本文研究了这样一个系统的SHM板状结构使用导波。该系统的基础是一个分布式阵列的永久连接的压电导波换能器，其中对换能器被用于一发一收配置允许检测和定位的板中的损伤。据观察，由于环境条件的变化，使用单一基线测量在中长期内会受到影响。不稳定性的一个关键参数是测试结构的温度变化。一种使用基线数据库的方法，称为最佳基线减法（OBS），描述并应用于实验SHM系统。本文的目的是研究在不同的温度变化率和它的使用在损伤定位的OBS的适用性和鲁棒性。结果表明，通过OBS的信号相干噪声比的改善高达20 dB，可以实现与单基线减法相比。
When testing complex structures using a deployable guided wave system, the measured signals are often far too complex to directly interpret without a priori knowledge of the geometry of the structure. However, in a structural health monitoring (SHM) scenario, the sensors are permanently attached to the structure and so changes in the system can be monitored by comparison to an earlier baseline measurement, taken when the structure was undamaged. This paper investigates such a system for the SHM of plate-like structures using guided waves. The basis of the system is a distributed array of permanently attached piezoelectric guided wave transducers where pairs of transducers are used in pitch-catch configuration allowing the detection and localization of damage in the plate. It has been observed that the use of a single baseline measurement suffers in the medium to long-term due to the variation of environmental conditions. A key parameter in the instability is the change in the temperature of the test structure. A method of using a database of baselines, termed optimal baseline subtraction (OBS), is described and applied to an experimental SHM system. The objective of this paper is to investigate the suitability and robustness of OBS under varying rates of temperature change and its use in the localization of damage. Results have shown that through the OBS an improvement of up to 20 dB in signal-to-coherent noise ratio may be achieved compared with single baseline subtraction.