Pulsed eddy current thermography: System development and evaluation
Pulsed eddy current thermography: System development and evaluation
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DOI：
10.1784/insi.2010.52.2.87
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发表时间：
2010-02
期刊：
影响因子：
1.1
通讯作者：
John Wilson;G. Tian;I. Z. Abidin;Suixian Yang;D. Almond
中科院分区：
文献类型：
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作者：
John Wilson;G. Tian;I. Z. Abidin;Suixian Yang;D. Almond
需要快速且有效的技术来检查工程结构和复杂部件，例如飞行器涡轮机叶片，以识别潜在的故障部位。脉冲涡流（PEC）热成像是一种新的检测技术，它允许用户使用红外成像捕获部件或结构中的涡流分布，并在相对较宽的区域内检测缺陷。该技术适用于具有合理电导率水平的材料，并具有检测涂层下缺陷的能力。然而，与其他热成像检测技术相比，PEC热成像技术受到的关注相对较少。本文详细介绍了PEC热成像检测系统的设计、开发和优化，包括样品整体和局部加热线圈的设计、激励参数（频率、功率、脉冲宽度等）的优化以及摄像机的选择。该系统用于检查几个真实世界的样品，使用不同的线圈设计，并使用新开发的特征提取技术的结果进行评估。工作表明，与明智的线圈设计和激励参数的选择，PEC热成像可以用来获得定量信息，通过分析的表面加热模式和瞬态温度变化的缺陷表征。
There is a need for fast and efficient techniques to inspect engineering structures and complex components such as aircraft turbine blades to identify potential sites of failure. Pulsed eddy current (PEC) thermography is a new inspection technique which allows the user to capture the eddy current distribution in a component or structure using infrared imaging and detect defects over a relatively wide area. The technique is applicable to materials with a reasonable level of electrical conductivity and has the ability to detect defects under coatings. However, PEC thermography has received relatively little attention compared to other thermographic inspection techniques. In this paper, the design, development and optimisation of a PEC thermography inspection system is detailed, including coil design for global and local heating of samples, optimisation of excitation parameters (frequency, power, pulse duration etc) and camera selection. The system is used to inspect several real-world samples, using different coil designs, and the results are assessed using newly developed feature extraction techniques. The work shows that with judicious coil design and selection of excitation parameters, PEC thermography can be used to obtain quantitative information for defect characterisation through analysis of the surface heating pattern and the transient temperature change.