Compensation of phase response changes in ultrasonic transducers caused by temperature variations
Compensation of phase response changes in ultrasonic transducers caused by temperature variations
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DOI：
10.1177/1475921718759272
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发表时间：
2019-03-01
影响因子：
6.6
通讯作者：
Cegla, Frederic
中科院分区：
文献类型：
--
作者：
Herdovics, Balint;Cegla, Frederic
结构健康监测的最大挑战之一是对环境和操作条件的监测数据进行补偿。为了可靠地估计结构的变化，在进一步分析信号之前，必须补偿环境和操作条件对超声波信号的影响。温度引起的传播速度变化对超声波信号的影响最大，并已被彻底研究。本文探讨了微妙的，但也是非常重要的，在传感器输出的变化所造成的工作温度的变化。提出了一种补偿方法，该方法同时补偿换能器相位响应变化和波的传播速度变化。所提出的补偿方法的一个关键的实际特征是，它只使用超声波信号本身进行补偿估计，并且可以用于任何类型的超声波，而不管换能器的类型。为了演示的目的，在这篇文章中，结果显示为零阶扭转导波，获得了一个专门建造的电磁声换能器。对于温差为41.5摄氏度的信号，与标准方法相比，所提出的补偿方法能够将环境和操作条件的影响进一步降低20 dB（回波尾部为7 dB）。这导致对接收到强反射的区域中的缺陷的高得多的灵敏度。此外，对于所提出的测量设置，可以估计的波传播速度的温度依赖性变化的精度提高了15%。
One of the biggest challenges in structural health monitoring is the compensation of monitored data for environmental and operational conditions. In order to reliably estimate the changes in the structure, it is essential that the effects of environmental and operational conditions on the ultrasonic signal are compensated for before the signals are further analysed. The temperature-induced propagation speed change has the biggest effect on the ultrasonic signal and has been thoroughly investigated. This article investigates the subtler, yet also very important, changes in transducer output resulting from changes in the operating temperature. A compensation method is proposed which compensates for both the transducer phase response change and the wave's propagation speed change. A key practical feature of the presented compensation method is that it uses only the ultrasonic signal itself for compensation estimation and can be used for any type of ultrasonic wave regardless of the type of transducer. For demonstration purposes, in this article, the results are shown for zero-order torsional guided waves, acquired by a purpose-built electromagnetic acoustic transducer. For signals with a 41.5 degrees C temperature difference, the proposed compensation method was able to reduce the effect of environmental and operational conditions by 20 dB further (7 dB at the tail of the echo) compared to standard methods. This results in a much higher sensitivity to defects in areas where strong reflections are received. Furthermore, for the presented measurement setup, the precision to which the temperature-dependent change in wave propagation speed could be estimated was improved by 15%.