Dynamic torsional characteristics of mine hoisting rope and its internal spiral components

Abstract

Dynamic torsional characteristics of mine hoisting rope and its internal spiral components were investigated in the present study. Theoretical models of tensions of rope segments at distinct locations were presented to obtain dynamic rope tensions. Theoretical models of torque, unit torsion angle, torsion angle, twisting parameters, and torsional stress were introduced to investigate dynamic torsional characteristics of hoisting rope and its internal spiral components under tension. Rope tests were conducted in order to validate dynamic torsional properties of the rope under fluctuation tensions. The results show three-stage fluctuating trends of rope tension and torque. An increase of hoisting time induces a decreased torsion angle of the rope, fluctuating upward trends of unit torsion angles of the rope, spiral strands and steel wires, respectively, fluctuating increases in lay angles of the spiral strand and steel wires, respectively, and the fluctuating decreased lay length of the spiral strand. An increase of the distance between rope segment and friction pulley tangent causes a decrease at first and then an increase in the unit torsion angle in cases of the rope, spiral strands and steel wires, an increase at first and then a decrease in the rope torsion angle, increased lay angle and decreased lay length of the spiral strand, a decrease at first and then an increase in the torsional stress of steel wire in every layer of the spiral strand.