Elastic Wave Propagation in Wire Cable for Corrosion Monitoring and Evaluation

Abstract

The propagation of elastic waves in wire cables was evaluated. An elastic wave was excited and detected using the pitch-catch method and a pair of piezoelectric transducers. The group velocity dispersion was calculated using the wavelet transform of the time domain signal. The calculated wavelet contour map did not correspond to the theoretical group velocity dispersion curves for a wire and a rod with the same wire cable diameter when no tensile force was applied. The amplitude of the waveform in each wire was different, and the differences were thought to be caused by a nonuniform contact force. The time domain signals from different tensile forces were then compared. The maximum amplitude of the time domain signal increased with increasing tensile force; however, the rate of increase was different for each wave packet. The calculated wavelet coefficient corresponded to the theoretical group velocity dispersion curve for the F(1,1) mode of a rod with the same wire cable diameter when a tensile force was applied.