A machine for the tension-torsion testing of steel wire ropes

The development of steel wire ropes for ultra deep level hoisting requires careful consideration of their torsional behaviour under service conditions. Rope load differentials in a deep shaft cause significant permanent variations of lay angle along the rope length which can have negative effects on the rope endurance. Laboratory based experimental investigations can therefore be of great benefit to rope manufactures in the assessment of the torsional characteristics of rope constructions. lt is in view of this reasoning that an advanced machine for the tension-torsion testing of steel wire ropes has been developed at the CSIR laboratories in Johannesburg. This introductory paper discusses the construction and capabilities of the computer controlled hydraulic testing facility. The methods used for axial load, torque, twist, elongation, diameter and lay length measurement are addressed and the machine control system is described. For illustration, examples of results for constant twist, load and torque tests have been included. These tests were conducted on a 40 mm diameter, right hand Lang's lay, triangular strand rope.

Author(s): G. Rebel & H. D. Chandler