Investigations Regarding the Relation between the Number of Torsions of the Wires and the Fatigue Strength under Repeated Bendings of the Ropes

The number of torsions of the single wires is generally considered as being important for the judgement of the rope quality. The minimal number of torsions necessary for the acceptance of the wires and the ropes respectively is laid down in the Standards. This minimal number, however, is subject to incessant contestations because there is only a very insufficient number of exact data existing with regard to the relation between the number of torsions of the wires and the operational performance of the ropes. The Institute for Construction Equipment and Transportation Machinery of the Swiss Federal Institute of Technology in Zurich has recently twice been fortunate enough to obtain relatively suitable test material and thus to be able to carry out the appropriate comparison tests. The following is a report on these investigations, conscious of the fact that our work cannot offer more than fragmentary contributions to the solving of this problem.

Author(s): G. Oplatka & M. Roth