Damage detection of anchored region on the messenger cable based on matching pursuit algorithm

摘要

The messenger cable is the main bearing part of the electrified railway catenary. Damage is easily generated in the anchored region and difficult to detect, and will cause a major accident if left unchecked. At present, the damage detection method is mainly for the bare part of the strand, but rarely about the covered region. Therefore, this paper proposes an ultrasonic guided wave detection method, which is based on matching pursuit algorithm and the developed chain detection device to monitor the region covered by the mid-anchor clamp. Firstly, according to the propagation characteristics of the ultrasonic guided wave in the stranded structure, the pulse echo detection method was adopted and the arrangement of piezoceramic transducers was determined. Secondly, the mechanism between the guided wave and the damage was analyzed by the matching pursuit algorithm in finite element simulation. Then, a chain detection device was designed based on the detection method and simulation results. Finally, a series of experiments were carried out under different temperature conditions and different tensile stress conditions. The experimental results show that the damage depth over 2.5 mm on single-wire can be detected by the proposed method, which satisfies the detection requirements of electrified railway messenger cable. This research provides an effective method for detection the catenary damage of electrified railway. (C) 2019 Published by Elsevier Ltd.