Bending tests on circular braided ropes under variation of different peripheral test conditions

Abstract

Various companies are working on the utilisation of high performance fibre ropes (HPFR) in industrial cranes and conveyor systems. In a collaboration between Konecranes and TUC, application-relevant influencing variables on bending wear were investigated experimentally. This paper summarizes these test results from single cyclic bending over sheave (CBOS) tests on circular braided ropes. The ropes investigated are single-ply, uncovered circular (round) braided ropes made of UHMW-PE yarns. The ropes are industrially manufactured and have a coating. Different factor levels were varied as part of the investigations. These are i) the strand load (referred to as safety factor), ii) the angle of entry of the rope on the test sheave (referred to as fleet angle), iii) the test sheave material (variation between polyamide PA and steel ST sheaves), iv) the bending ratio BV (as the ratio of the uncoiling diameter D to the rope diameter d) and v) the ambient temperature in the bending zone (referred to as TBZ in the following). Finally, the results are compared and a known service life model is applied.