A coupling EMI and Ultrasonic guided wave nondestructive testing method to detect the damage of multicore cable structure

Multicore cable structure is widely used in power systems, transportation, construction, and other industries. As a critical component of the most essential structural parts, it is the focus of daily safety testing. The structural health detection method provides a feasible idea for multi-core cable defect detection. However, the existing methods are difficult to carry out damage detection and reliable evaluation. A coupling nondestructive detection method is proposed, which combines the base, EMI, guided wave, and piezoelectric ceramic transducer (PZT) and keeps the advantages of the two methods. It couples the cable and the base into a whole and reflects the change of system impedance through the overall impedance to detect the defection. Meanwhile, it couples the guided wave into the cable and keeps the waveform and phase unchanged to extract the damage information. The results show that the amplitude of the impedance spectrum decreases and the phase shifts when the damage occurs. It also shows a full coverage coupling guided wave excitation which is excited by ring base array, and avoids the guided wave coupling caused by cable contact, and keeps the damage information in the echo signals.