A methodology for cable damage identification based on wave decomposition

Abstract

Vibration-based damage identification has been widely studied in the field of structural health monitoring (SHM) for several decades. It is well known, however, that low-order modal parameters, being among the most frequently used, are not sensitive to local damage. A suitable methodology is therefore needed to extract such damage features from the dynamic response of structures. In the present work, local bending behavior of cables is studied for damage identification. First, the dynamic response of a cable is decomposed into evanescent wave and propagating wave components. It is proven that the contribution of the evanescent wave is spatially concentrated, and is sensitive to local damage. A signal transform is proposed next, which allows the estimation of the wave components from the measured cable response. The reflection coefficient of the evanescent wave (REW), which can be calculated from the estimated wave coefficients, depends only on the characteristics of the local discontinuity, and proves to be a robust indicator for local damage. The feasibility of the proposed methodology is studied by means of a simulated experiment, considering a cable model with two locally damaged parts. The results show that the intensity of REW is significantly higher near the damage locations, allowing damage localization. From the estimated REW near the damage locations, the damage levels can be estimated, showing the potential of this methodology for damage assessment of cable structures.

Piezoelectric Transducers for Structural Health Monitoring of Joint Structures in Cylinders: A Wave-Based Design Approach

“…Considering Equations (14) and (15) and Equation 12, a, b, c, and d can be solved. As an example, the excitation frequency is 132kHz, as given in Section 5.2, and the axial force of 100N is applied at the right end.…”

“…Researchers have also developed analytical and numerical methods to study the interaction between damage and wave-mode conversion. Zhang et al [15] decomposed the frequency-domain response of a cable into an analytical four-wave basis and used the evanescent wave amplitudes induced by discontinuities as indicators of damage. Ichchou et al [16] developed WFEM with the diffusion matrix method (DMM) and analyzed the wave-mode conversion of a block coupling structure with a notch.…”

Cable Force Identification Based on Bending Waves in Substructures

“…Doyle [18] and Lee et al [19] proposed a spectral element method to analyze the dynamic response of a continuous mass system, which overcomes the limitation of the finite element method to divide a large number of elements and greatly increase the calculation amount. However, based on the Euler-Bernoulli beam, Zhang [13] deduced the cable spectral element of Timoshenko and increased its applicability. However, as described in Section 1, the theory of the Timoshenko beam has issues.…”

“…Since the distributed axial force can be approximated as a single value only in the local area for the cable, the identification of the internal force state of the whole cable demands further discussion. Zhang [13] proposed a new theory of cable force identification in his doctoral dissertation by using the Timoshenko beam model to deduce the frequency domain solution of cable vibration, which could calculate the frequency domain response of the cable and by spectral element programming. In his paper, the four-wave components existing in the beam model are not discussed; instead, five points of subcable segment are selected for least squares solution of the wave component coefficient [14], taking wave component coefficient of fitting residual error minimum as a criterion of cable force identification.…”

Friction and Wear Mechanism Analysis of Polymer Flexible Cable Using a High Natural Frequency Piezoelectric Sensor

“…It has shown the importance of friction and wear in contact wires. Songhan Z. et al studied the friction and wear damage of the cables under local bending behavior, based on the vibration damage identification technology [7]. When people realized the importance of friction and wear on rigid cables (rigid cables made entirely of metal conductors, such as transmission cables, contact wire).…”