Swaged fittings under tension and fatigue loads

Although swaged terminals have become increasingly important for structural engineering and mechanical handling, no technical standards exist either for production or structural analysis. Due to the complex behaviour of the components (terminal and wire rope) analytical calculations are not available to estimate the load capacity of swaged terminals under tension or fatigue loads. Only a few design recommendations are available, which are based on geometric parameters and experimental data. Therefore the load capacity of the swaged terminal was investigated in a PhD thesis1 at the University of Stuttgart. The task was split into a theoretical and an experimental section. Analytical formulas were derived using the Finite-Element-Method to describe the behaviour of wire rope and sleeve after swaging. For this wire rope termination in combination with open spiral strands the fatigue properties were investigated in a systematic test program. Due to the non-uniform methods of analysis, available test results cannot be applied directly to other rope constructions and terminations. Current standards define endurance loads for defined rope types and termination such as cast sockets. For a safe dimensioning it is necessary to specify mechanical closure and fatigue conditions considering stress and amplitude depending on swaging parameters and material.

Author: D. Raupp