Bend Fatigue Resistance
Bend fatigue resistance is the ability of the wire rope to withstand repeated bending under constant or fluctuating loads. As the load increases in any reeving system so the rate of fatigue will increase. As bending radii decrease in a reeving system so the rate of fatigue will increase.
A wire rope which has an increased number of wires such as 6x36 construction will have greater resistance to fatigue than a 6x19 construction.
Extra fatigue life can be achieved by moving to compacted rope.
The compacted strand has very favourable internal and external contact conditions when compared with the point contact of round wires within a conventional strand.
The smooth surface of compacted rope offers a wider bearing surface to the sheave or drum groove. Increased fill factor, lowering internal stress levels, combined with improved internal and external contact conditions lead to longer rope life.
Laboratory fatigue testing indicates that it is possible to achieve up to two times normal rope life when comparing compacted rope with a conventional rope of equivalent construction.
The smooth external surface of compacted rope can also lead to less wear on the sheave and winding drum.