Wendel Frick
Research Assistant
University of Stuttgart - Institute of Mechanical Handling and Logistics IFT
Research Assistant
University of Stuttgart - Institute of Mechanical Handling and Logistics IFT
Relationships between static deformation behavior and dynamic fatigue behavior of wire ropes under tension-tension loading
Constructions and Design EngineeringRopes are load-controlled components and stress safety is considered relevant for lifetime. However, it is observed that lifetime of ropes loaded by tension-tension can increase with increasing mean tension. This observation cannot be explained by a stress-based safety concept.
This means that fatigue of ropes and their lifetime is not load-controlled. This observation is consistent with the general scientific findings on the fatigue behavior of metals, which states that the applied strain is the decisive parameter with regard to material fatigue.
The cause of the mean-stress-dependent fatigue behavior of ropes is their nonlinear deformation behavior, which means that the rope stiffness is not constant but depends on the applied elongation, i.e. at a comparable higher stress safety a shorter lifetime occur. Thus, the author promotes a strain safety concept for lifetime approach of ropes.
