This paper describes the detectability of eddy current testing (ECT) using directional eddy current for detection of in-plane fibre waviness in unidirectional carbon fibre reinforced plastic (CFRP) laminate. Three different types of probes, such as circular driving, symmetrical driving and uniform driving probe, were proposed, and the waviness angle was extracted from the contour map of the ECT signal by applying a Canny filter and a Hough transform. By comparing both the waviness angle estimated by ECT and that obtained by an X-ray CT image, the standard deviation (precision) and root mean square error (accuracy) were evaluated to discuss the detectability of these probes. The directional uniform driving probe shows the best detectability and can detect fibre waviness with a waviness angle of more than 2° in unidirectional CFRP. The probe shows a root mean square error of 1.90° and a standard deviation of 4.49° between the actual waviness angle and the angle estimated by ECT. This article is part of the theme issue ‘Advanced electromagnetic non-destructive evaluation and smart monitoring’.

中文翻译：

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使用定向涡流对 CFRP 中的纤维波纹度进行差分式探头的可检测性评估

本文描述了使用定向涡流检测单向碳纤维增强塑料 (CFRP) 层压板中的面内纤维波纹度的涡流检测 (ECT) 的可检测性。提出了三种不同类型的探头，如圆形驱动、对称驱动和均匀驱动探头，并通过应用坎尼滤波器和霍夫变换从ECT信号的等高线图中提取波度角。通过比较 ECT 估计的波度角和 X 射线 CT 图像获得的波度角，评估标准偏差（精度）和均方根误差（准确度）以讨论这些探头的可检测性。定向均匀驱动探头显示出最好的可检测性，可以检测单向CFRP中波纹角大于2°的纤维波纹。探头显示出 1.90° 的均方根误差和 4.49° 的标准偏差，即实际波度角与 ECT 估计的角度之间的偏差。本文是主题问题“高级电磁无损评估与智能监测”的一部分。