Nonlinear Model for Full-Locked Coil Ropes Subjected to High External Radial Forces

This paper developed a nonlinear model for analysis of full-locked coil ropes under high external radial forces, in particular for prediction of deformations, stresses, and strains. This nonlinear model is based on homogenized layers and consists of the mathematical model in a generalized plane strain approach and the nonlinear model of orthotropic material properties. The material properties of each layer can be determined in the model in the radial and circumferential directions independently. The nonlinear characteristics of material properties have a significant effect on the mechanical behavior when multilayered wire strands are under high external pressure, e.g., as in the case of clenching. These nonlinearities considered in the model cover the contact mechanics of wires within and between layers, including geometrical and material nonlinearities for line and point contact as well as initial gaps between wires. The performance of the developed nonlinear model was presented and compared with experimental data and with a conventional linear approach. The predictions based on this nonlinear model matched the experimental data closely. The sensitivity of the results to geometrical tolerances was demonstrated. The results showed clearly that a linear approach is not appropriate for the investigated problem. The proposed nonlinear model is an accurate and effective method for calculation of the response of a rope under high external radial forces. It can be applied to any multilayered wire strand.