Study on multi-layer coupling contact performance of single-strand wire rope

Aiming at failure problems of single-strand wire rope caused by inter-wire contact in practical applications, the multi-layer coupling contact performance of a single-strand wire rope subjected to an axial torsional load was studied based on the elastic contact theory and thin rod theory. Firstly, considering the Poisson's ratio effect and the contact deformation, a coupled mathematical model for the axial mechanical property and contact performance between the wires of the rope was established. Then, a numerical scheme based on the semi-analytical method(SAM) was used to solve the coupling problem. During the solution process, the conjugate gradient method(CGM) and fast Fourier transform(FFT) were used to calculate the contact deformation, contact pressure and inside stress of the wires caused by the inter-wire contact. The evolution rules of the contact performance parameters between the different layers of the single-strand wire rope subjected to an axial torsional load were revealed. Additionally, the effect of the structure parameters on the contact behavior of the rope was discussed. Finally, the validity of the model was verified by comparison with the COSTELLO theory. The results show that the maximum contact pressure and deformation between the different layers of the single-strand wire rope occur at the contact centers under a torsional loading condition, and the relationship changes nonlinearly with the process of torsional loading. Stress yielding is most likely to happen at the contact area between the middle layer and the outer layer under a large torsional load. Compared with the middle layer spiral wire's lay angle, the lay angle of the outer spiral steel wire has a more significant effect on the contact between different layers of the rope. The maximum stress of steel wire caused by the torsional load locates below the contact interface, and the stress and the depth of the stress area increase with increasing lay angles of the spiral steel wires. © 2020, Central South University Press. All right reserved.