Steel strand is widely used as a key component in metallurgy, mining, petroleum, aerospace and other fields with its advantages such as high bearing capacity and good flexibility. For the steel strand which needs to be repeatedly wound around a drum, pulley or other parts in service, the internal steel wire frictional wear occurs due to the cyclic bending, resulting in the reduction of cross-sectional area of the steel strand and degradation of its bearing performance. Meanwhile, the load amplitude, geometrical structure and material properties will affect the improvement of the interwire tribological properties of the steel strand. Therefore, the interwire tribological properties of the steel strand under different service conditions were explored, which provided theoretical basis for the design and application of the steel strand.

Firstly, a numerical analysis model of interwire tribological properties of a steel strand subjected to cyclic bending load was built based on Kirchhoff-Love theory and Archard’s theory of wear, with the consideration of the interwire frictional contact and reciprocating sliding behavior within the strand, during which a semi-analytical method was adopted to realize the fast calculation.

Then, the present numerical model was validated through comparisons with Kirchhoff-Love theory and the finite element method, as well as a wear experiment. In addition, the results were consistent with the theoretical results, finite element simulation results and test data, respectively. It showed that the present numerical analysis model was able to give a reasonable evaluation of the interwire tribological properties of the steel strand under a cyclic bending load condition.

Finally, the distributions of tribological parameters such as wear depth, slip distance, contact pressure and contact deformation of the steel strand were studied. The influences of load amplitude, geometrical structure and material properties on the interwire tribological properties of the wire strand were also analyzed.

In conclusion, it was revealed that the interwire wear occurred outside the bending neutral layer, and no wear occurred where the interwire slipping distance was zero, no matter the wires were contacted or not. The greater the bending load, the more serious the wear. Additionally, an excessive load amplitude can cause serious stress concentration and local deformation, resulting in worn and broken wires. The effects of radius of outside wire and lay angle of the strand on the interwire tribological properties were analyzed. The results showed that the interwire contact pressure and interwire contact deformation increased with the increases of radius of outside wire and lay angle of the wire strand, which caused the increase of total wear depth. The increases of the radius and lay angle of the outside wires led to a constant length of the worn area along the interwire contact line and an increased size along the normal direction of the interwire contact line. The total wear depth of the wire strand increased with increasing elastic modulus and Poisson’s ratio of the wire material. The elastic modulus had a direct effect on the wear characteristics of the wire strand. The increment of Poisson's ratio of the steel wire material led to the increases of the contact deformation and slip distance between wires, causing excessive wear and even cracking between wires. As a result, the selections of small elastic modulus and Poisson's ratio were helpful to improve the wear resistance of the wire strand.