Effect of time-varying corrosion on the low-cycle fatigue mechanical properties of wire rope

Abstract

In this study, we investigate the macroscopic mechanical behaviour of wire rope corroded by seawater by analyzing the monotonic tensile and hysteretic behaviour of 6 × 19 S + IWR round strand steel wire ropes with different corrosion degrees. First, the wire rope samples were subjected to a full immersion accelerated electrochemical corrosion experiment, which revealed that the corrosion distribution is uneven, and that corrosion progresses from the outer wires to the inner wires through crevices in the wire rope. Scanning electron microscopy revealed that an increase in corrosion increases the number, length, and depth of microscopic cracks on the surface of the wire rope. The degradation effect of corrosion on the mechanical properties of wire rope differs significantly. As corrosion increases, the bearing and deformation capacities decrease substantially, and the fracture mode changes from ductile to brittle fracture. Based on the mechanical characteristics and the influence factors of a steady stress–strain cycle of a corroded wire rope, we proposed a hysteretic mechanical model consisting of a loading and unloading curve. The proposed model was verified using the experimental data, and can accurately reflect the influence of the corrosion degree and loading amplitude on the hysteretic characteristics of a wire rope.