Numerical and Experimental Investigation of Guided Wave Propagation in a Multi-Wire Cable

Abstract

Ultrasonic guided waves (UGWs) have attracted attention in the nondestructive testing and structural health monitoring (SHM) of multi-wire cables. They offer such advantages as a single measurement, wide coverage of the acoustic field, and long-range propagation ability. However, the mechanical coupling of multi-wire structures complicates the propagation behaviors of guided waves and signal interpretation. In this paper, UGW propagation in these waveguides is investigated theoretically, numerically, and experimentally from the perspective of dispersion and wave structure, contact acoustic nonlinearity (CAN), and wave energy transfer. Although the performance of all possible propagating wave modes in a multi-wire cable at different frequencies could be obtained by dispersion analysis, it is ineffective to analyze the frequency behaviors of the wave signals of a certain mode, which could be analyzed using the CAN effect. The CAN phenomenon of two mechanically coupled wires in contact was observed, which was demonstrated by numerical guided wave simulation and experiments. Additionally, the measured guided wave energy of wires located in different layers of an aluminum conductor steel-reinforced cable accords with the theoretical prediction. The model of wave energy distribution in different layers of a cable also could be used to optimize the excitation power of transducers and determine the effective monitoring range of SHM.

Guided wave‐based cable damage detection using wave energy transmission and reflection

“…The mesh size equaled 1.5 mm in the axis direction, meeting the requirement that the minimum wavelength has to cover more than 20 calculation nodes. [ 48 ] It consists of 448,768 linear solid hexahedral eight‐node elements. Contact conditions between wires were simulated using hard contact and friction in the normal and tangential directions with a friction coefficient of 0.6 [ 48 ] .…”

“…[ 48 ] It consists of 448,768 linear solid hexahedral eight‐node elements. Contact conditions between wires were simulated using hard contact and friction in the normal and tangential directions with a friction coefficient of 0.6 [ 48 ] . Dynamic explicit analysis was carried out on the model, which allows the automatic selection of time step.…”

Concentration profiling of a horizontal sedimentation tank utilising a bespoke acoustic backscatter array and CFD simulations

“…The probes were positioned at 20 o to vertically downwards, so that it was possible to measure a close-to-vertical profile distance without interference from each other. During measurement sequences, excitation was performed at frequencies of 2.0, 2.25 and 2.5 MHz using μs Hann windowed tone bursts (to reduce side lobe leakage (Zhang et al, 2019)) and the return pulse voltage was measured to a maximum depth of 300 mm. In total, 10,000 received waveforms were collected for each excitation setting and stored for post-processing (equating to ~ 3 minutes of acquisition time per measurement).…”

Experimental Investigations Regarding the Structural Damage Monitoring of Strands Wire Rope within Mechanical Systems

“…One other direction for non-destructive testing and damage detection in cables and wire ropes is represented by the investigations on guided wave propagation phenomena. Hereby, in [ 2 ], the authors analyzed the ultrasonic guided waves with application on SHM of multi-wire cables, because of their advantages, including requires a single measurement, large coverage of the acoustic field, and long-range propagation capability. This method presents some difficulties related to the propagation behaviors of guided waves and signal analyses, due to the mechanical coupling of multi-wire ensembles.…”