Influence of the plastic bending deformation on the lifetime of wires

RoundTable – ENDURANCE RESEARCH OF WIRE ROPE AND ITS PRACTICAL APPLICATIONS – Glasgow 1985

If a rope has been plastically deformed under the action of some external force, the question arises whether, after the necessary straightening, this rope will still be fit to use and, if so, what reduction of the lifetime has to be expected. In order to find an answer to this question, tests with ropes are presently being carried out at the Swiss Federal Institute of Technology, Zurich. To complete and shorten these rope tests, examinations of individual wires were carried out at the same time. During these tests, rope wires of different breaking strengths were at first plastically deformed with varying intensity, and subsequently tested with regard to their residual breaking and fatigue strength. The plastical deformation was due to reverse bending. Similarly to the stress acting in ropeway cable wires, the fatigue strength was determined with a constant tensile force, repeated bending and surface pressure.

Author(s): G. Oplatka, M. Roth & P. Vaclavick