Breaking Strength and Bending Fatigue Resistance of Wire Rope
There are many benefits found when using wire ropes and nylon slings. These ropes are used because they are flexible, efficient, and reliable. Of all their characteristics, the two most desirable are bending fatigue resistance and high breaking strength.
Breaking Strength: to calculate the breaking point of a particular wire rope, you must take the metallic cross-section of a steel wire rope and then multiply that by nominal tensile strength. To get the minimum breaking strength, take the calculated breaking strength of the wire rope and multiply it by the spin factor. The actual breaking strength is only determined with a breaking test.
It is possible to increase the overall breaking strength of steel wire ropes by increasing tensile strength. Doing this increases the whole metallic area of the verope.
Bending Fatigue Resistance: the characteristic is defined as the total number of bending cycles achieved by a rope during a bending fatigue test. This test happens under defined parameters, such as running over a sheave and a predetermined line pull that corresponds to the MBL of wire ropes.
To increase the resistance of the wire, the contact areas between sheaves and wires must be increased. This happens by adding an extra plastic layer between outer strands and the IWRC.