Study of wave propagation in a multiwire cable to determine structural damage

Multiwire cables are widely used in engineering structures, even though there is a growing concern about the presence of environmental degradation, random overloads, and corrosion affecting their structural integrity. In this work, propagation of guided waves in a multiwire aluminium conductor steel reinforced cable (ACSR) for structural damage detection is studied using time–frequency analysis based on short time Fourier transform (STFT). Identification of propagation vibrational modes and measurements of mode energy amplitude are used to correlate the spectral energy change to the extension of an artificial damage introduced to the cable sample by a notch transversal to the pulse propagation. The results showed that mechanical contact among the wires generates mode conversion of longitudinal to flexural modes.