Reliability and damage analysis of a helical strand taken from a steel cable

Wire ropes are essential components in lifting and handling systems, ensuring both the transmission of mechanical forces and operational safety. Their structure, composed of several strands wound helically around a central axis, provides the ropes with an optimal combination of flexibility, strength, and reliability. Among these components, the central helical strand plays a crucial role in the overall mechanical strength of the entire rope, absorbing a large portion of axial loads and contributing to stress distribution. However, during operation, this strand can suffer progressive damage due to wear, corrosion, or localized mechanical failures, which can lead to premature failure.

The main objective of this work is to study the damage mechanisms of this central strand and assess their impact on its mechanical performance. To this end, static tensile tests were conducted on new strands as well as on strands artificially damaged by shearing 1, 2, or 6 constituent wires, to simulate different levels of degradation. The experimental results made it possible to analyze force-displacement curves, determine mechanical characteristics (strength, stiffness, elongation), and observe failure modes.

Interpretation of these data highlights a clear correlation between the degree of initial damage and the reduction in the strand's structural reliability. This study thus provides new insights into the fatigue and failure behavior of damaged strands and provides a technical basis for implementing more effective preventive maintenance strategies in systems using wire ropes.