Phenomena Investigation of Guided Waves Propagation in a Multiple-Wire Cable with Gradually Increasing Cut Depths

Abstract

In this study, the propagation phenomena of guided waves in a multiple-wire Aluminium Conductor Steel Reinforced (ACSR) cable with artificial cuts were investigated. A two piezoelectric transducers system, in a pitch and catch configuration, together with the wavelet transform, was employed for analyzing guided wave propagation. An ACSR cable, 0.9m in length and total diameter of 22.1mm, made of 7 steel wires and 26 aluminium wires was employed. Artificial damage was made at 0.45m from the emitter transducer; cut depth in the cable was gradually increased from 1mm to 9mm. The transducers were attached to the ends of the ACSR cable using a liquid coupling medium. A function generator was used to drive the transmitter transducer with five cycles of 500 kHz sinusoidal waves. The received guided wave signals were amplified and acquired by a digital oscilloscope that sent the data to the computer for further analysis. From this, the following conclusions were obtained: a) the modes identified using time- frequency analysis before and after the cut were L(0,1) and F(1,1) for steel and aluminium, respectively; b) the amplitude of the received L(0,1) signals increased with the increase of the cut depth, depicting an exponential behaviour, conversely the F(1,1) modes decreased, suggesting a mode conversion from F(1,1) to L(0,1) modes due to loosed friction contact among individual wires.