The determination of the fatigue life of wire ropes based on an analysis of stresses in wires

RoundTable – ENDURANCE RESEARCH OF WIRE ROPE AND ITS PRACTICAL APPLICATIONS – Glasgow 1985

The varying loads of the rope and the position of wires in the rope make that the individual wires work in the condition of the triaxial state of alternating stresses. In the rope wires exist the following kinds of stresses:
- normal and tangential caused by axial forces active in a rope,
- normal and tangential connected with the variations of the
curvature of the wire axis during the approach of the rope to
the sheave,
- shear stresses caused by friction forces in the points in which
rope wires contact with the sheave groove,
- normal and shear stresses connected with the transmission of the
transverse force to the sheave by individual rope wires,
- contact stresses occuring in the points where rope wires contact
with the groove,
- technological - normal and tangent stresses dependent on the rope
production process and acting even in an unloaded rope. Stresses in bent ropes vary in a wide range even by the assumption of the constant tensile force in the rope. Stresses which occur in the rope wires are much higher from those which exist in other machine components despite the large value of safety factors.

Author(s): J. Hansel & W. Olesky