Effect of high mean tensile stress on the fretting fatigue life of an Ibis steel reinforced aluminium conductor

The aim of this work is to evaluate the effect of a high mean tensile pre-load on the fatigue life of an Ibis type of steel reinforced aluminium conductor (ACSR) mounted on a monoarticulated cast aluminium suspension clamp. To carry out the tests a new and enhanced version of a fretting fatigue rig for overhead conductors was built. Based on the obtained S–N curves for this assembly it was shown that an increase of the Everyday stress (EDS) from 20% to 30% of the cable rated tensile strength (RTS) caused an average reduction of 50% in life. Failure analysis revealed that cracks always initiated at contact interfaces within the cable/clamp assembly, at the fretting marks.