Effect of rope twist and strand twist on the contact pressure between strands in Aramid fibre three-strand ropes

It is crucial to understand how internal pressures develop in para-aramid three-stand ropes with different pre-tension configurations in order to predict internal degradation during the rope lifetime. This study focuses on how the internal strand/strand pressure of para-aramid three-strand ropes subjected to applied tension loads is affected by rope twist and strand pre- twist.

The objective was investigated through a series of tensile tests on three-strand ropes with various twist configurations. The internal strand/strand pressure was measured using pressure films as the rope samples were subjected to increasing tensile loads.

The experiment's findings show that the internal pressure between the strands increased by increasing rope twist or strand pre-twist, or the applied tension load. Increasing strand twist reduces strand-strand interface flattening, implying stronger inter-fibre forces in the strand. Future studies will focus on analytical and numerical modelling to investigate and model the mechanics behind the observed behaviour.

Author(s): O.Allan, T.MIshra, M.B. de Rooij