A new probe‐based electromagnetic non‐destructive testing method for carbon fiber‐reinforced polymers utilizing eddy current loss measurements

Abstract

AbstractEddy current testing (ECT) is a widely used technique for detecting defects in carbon fiber‐reinforced polymers (CFRPs) at high frequencies. However, designing high‐frequency systems can be challenging, and high noise levels can be problematic. To address these issues, non‐destructive testing (NDT) methods that can detect CFRP defects at lower frequencies must be explored. In this study, a novel NDT method for detecting defects in CFRP at low frequencies was proposed. This method is an alternative to pulsed eddy current thermography and can achieve similar detection and imaging results at low frequencies. Furthermore, the developed method has a simpler structure and is easier to implement. This method uses the eddy current loss to characterize the thermal power of the eddy current in CFRP. A new probe was used to detect the eddy current loss to inspect the CFRP. The effectiveness of the proposed method was experimentally verified using different types of CFRP samples based on the C‐scan technology. The scanned images demonstrate that the developed method can provide appropriate detection results up to a frequency of 750 kHz. Furthermore, rotation experiments were performed to detect the fiber direction; the proposed method successfully detected the fiber direction up to 750 kHz. Thus, the proposed method can improve the detection of defects and enhance the longevity of CFRP components. Future work will focus on enhancing the sensitivity of this method at even lower frequencies.