Ju Taeho, Findikoglu Alp T
Materials Physics and Applications (MPA), Los Alamos National Laboratory, Los Alamos, NM 87545, USA.
Sensors (Basel). 2022 Nov 9;22(22):8647. doi: 10.3390/s22228647.
Ultrasonic testing (UT) has been widely used for the Nondestructive Evaluation (NDE) of pipes due to its many favorable characteristics. However, one of the main challenges in the general use of UT for real-world pipelines is the sensitivity of this method to environmental and operational condition changes. This paper proposes a new UT method with enhanced compensation for environmental effects and operational condition changes. In particular, the effectiveness of the new method is tested in the presence of temperature variations, and changes in water flow rate inside a stainless-steel pipe. The proposed UT method uses multi-mode and broadband guided ultrasonic waves in the pipe walls, excited and received by single-element ultrasonic sensors that are spatially separated, forming a measurement zone between any pair of such transmit and receive sensors. Amplitude changes, time shifts, and frequency content variations in the ultrasonic signal due to temperature changes and water flow are evaluated and compensated for reliable UT of mechanical changes in the pipe. It is observed that spurious effects of water flow on ultrasonic response, if not properly compensated, can dominate over effects due to actual mechanical changes, but such liquid-boundary effects can be compensated effectively by the proposed time- and frequency-filtering method.
由于具有诸多优良特性，超声检测（UT）已广泛应用于管道的无损检测（NDE）。然而，在实际管道中普遍使用超声检测的主要挑战之一是该方法对环境和运行条件变化的敏感性。本文提出了一种新的超声检测方法，该方法增强了对环境影响和运行条件变化的补偿能力。特别是，在存在温度变化以及不锈钢管内水流速变化的情况下，对新方法的有效性进行了测试。所提出的超声检测方法在管壁中使用多模式和宽带导波，由空间分离的单元素超声传感器激发和接收，在任意一对这样的发射和接收传感器之间形成一个测量区域。对由于温度变化和水流导致的超声信号中的幅度变化、时间偏移和频率成分变化进行评估和补偿，以实现对管道机械变化的可靠超声检测。可以观察到，如果水流对超声响应的虚假影响没有得到适当补偿，可能会超过实际机械变化所产生的影响，但通过所提出的时间和频率滤波方法，可以有效补偿这种液界效应。
