Numerical assessment of the damage-tolerance properties of polyester ropes and metallic strands

Abstract

Experimental and numerical studies have concluded that two of the main phenomena that govern the static response of damaged ropes and strands are the strain localization and asymmetry in damage distribution. In this paper, the dependency of the damage-tolerance properties and the accumulated damage level experienced up to the onset of failure on these two phenomena is investigated. To this end, a nonlinear model that couples the effects of these two phenomena is utilized to study the static response of damaged polyester ropes and metallic (steel and aluminium) strands. In particular, the residual stiffness, the residual strength, the reduction in the deformation capacity, and the accumulated damage, based on residual toughness values, are computed for a wide range of initial damage levels exerted on the ropes and strands. Experimental static tensile test data are used to validate the predictions provided by the nonlinear model in which initial damage levels and specimens diameters vary from 5% to 55% and 6mm to 166 mm respectively. Results indicate that the nonlinear model is capable of establishing the main phenomena that rules specimens response providing an accurate prediction of the damage tolerance-parameters and the damage level accumulated at the onset of specimens failure.