Theoretical and experimental approaches to studying additional stresses in elements of steel wire rope sduring winding on sheaves and drums

Abstract

DOI: https://doi.org/10.32820/2079-1747-2024-33-30-37

The article discusses theoretical and experimental approaches to studying additional stresses that
arise in elements of steel wire ropes during winding on sheaves and drums. The problem statement
highlights the importance of this issue for a wide range of industries utilizing steel wire ropes and the
necessity to increase their strength, reliability, and durability. The main part of the work presents various
formulas for determining additional stresses, proposed by domestic and foreign researchers such as V.A.
Malinovsky, I.F. Nikitin, M.F. Glushko, S.T. Sergeev, J. Benoit, I. Isaacsen, U. Ernst, Leider, K.
Schmidt, and others. It is noted that most of these formulas are applicable only to spiral ropes and do not
account for the design features of double-lay ropes. The comparison of additional stress values
calculated and experimentally obtained by I. F. Nikitin demonstrates significant discrepancies between
them. Further, the article examines experimental methods for determining stresses used by various
researchers in detail. Special attention is given to I.F. Nikitin's experiments, where U-shaped strain
gauges were used to measure deformations of diametrically opposite strands of wires in the rope,
excluding the influence of bending and torsion. The oscillograms of additional stresses obtained in his
experiments are presented, emphasizing these were direct measurements of additional stresses. Other
researchers, like Vik and G. Schiffner, glued strain gauges on the outer strands of wires and measured
combined stresses of tension and bending, obtaining corresponding oscillograms. K. Schmidt's work
presents results from three series of experiments for indirectly determining additional stresses, based on
measuring internal construction friction torque, rope deflection under transverse loading, and
determining fatigue strength under alternating bending on sheaves. Summarizing the results of various
experiments, K. Schmidt concludes on the magnitude of double amplitude stress oscillations in the wire
when it falls on the convex and concave sides of the rope for different rope constructions and lubrication
quality. However, the author emphasizes that in all these studies, additional stresses were considered as
fully formed by sliding friction forces between wires during their relative displacement, which does not
account for several other factors.