Influence of corrosion on the mechanical behavior of strand of a non-rotating wire rope: experimental study

Abstract

Wire ropes are a complex hierarchical structure. They consist of several wires that are twisted together to form a structure with strong mechanical properties. These properties make cable an essential element applied in civil engineering, industry development and maritime industrial services. Nevertheless, the cables in service are subject to many variable loadings. They are related to mechanical, thermal and environmental effects that lead to different degradation mechanisms, which can occur alone or in combination. The corrosion effect is one of these mechanisms, which can cause accelerated damage to rope components and thus lead to sudden and unexpected failure. For this purpose, experimental tensile tests were conducted on virgin and corroded strand samples constituting the 19x7 non-rotating steel wire rope to obtain the mechanical properties and predict the evolution of damage, as well as the life span of this strand. A mathematical model was developed to represent the damage to the strand. First, we adapted the theories of failure force using a coefficient related to the nature of the examined material. This coefficient was designed by considering two forces and giving a good approximation of the evolution of the experimental failure forces through the theoretically corrected failure forces using the modified Faupel’s formula. Then, the evolution of the theoretical damage can be deduced using the calculated forces. The different phases of damage and the critical life fraction that can lead to sudden failure of the wire rope were defined using these damage models. These techniques are important tools for industrialists to predict the service life of wire ropes and as well as establish a robust maintenance system that ensures the ability to operate in a safe and reliable environment.