Analysis of the coupled axial/torsional behaviour of spiral strands, wire ropes and locked coil cables.
Extensive comparative studies have been undertaken on various
theoretical approaches used for analysing spiral strands, in order to
identify their appropriate ranges of applicability. Based on the findings of
this exercise, a theoretical model is proposed for analysing the coupled
axial/torsional response of a stranded wire rope with either an independentwire
rope or fibre core.
A theoretical model is also proposed for the analysis ofaxial/torsionai
coupling of locked coil cables, regarding which, there was previously a
. paucity of reliable analytical or experimental information, despite their
wide range of applications. Axial hysteresis of locked coil cables is
estimated, and it is shown that it is significantly higher than the axial
hysteresis associated with spiral strands.
Simplified routines which are amenable to hand calculations are
developed for obtaining the no-slip stiffness coefficients for the coupled
axial/torsional stiffness matrix of axially preloaded spiral strands, with
the effect of hydrostatic pressure on sheathed strands catered for.
Moreover, the concept of orthotropic sheets for calculating the pattern of
interwire/interlayer contact forces in spiral strands is used to determine
the recovery length of a broken wire in any layer of a multi-layered
Wherever possible, the final theoretical results are compared with
experimental data from the available literature and very encouraging
correlations have been found in all cases.