Ultrasonic guided wave-based testing technique for inspection of multi-wire rope structures

•Propagation of ultrasonic guided waves along a multi-wire rope has been investigated.•The asymmetric distribution of amplitudes around the multi-wire rope was obtained.•Special ultrasonic contact-type ultrasonic transducers were developed.•The amplitude drop over defective strand was observed.•The technique for identification of particular defective strands has been developed.

The aim of this paper is to investigate the propagation of ultrasonic guided waves (UGW) along multi-wire ropes with polymer cores and to determine whether it is possible to detect defects and to identify a defective strand inside the internal structure of a multi-wire rope. The modes of UGW that propagate along multi-wire ropes have been identified using modelling wherein dispersion curves are calculated using the semi-analytical finite element (SAFE) technique. The optimal excitation regions were estimated using 3D FE modelling. An ultrasonic testing technique to identify particular defective strands inside the internal structure of a multi-wire rope was developed and verified experimentally.