Wire Rope Stretch/Elongation
Wire Rope Stretch/Elongation
(OP)
I am trying to calculate the elongation of wire rope as a fuction of load. I understand that it will be based on the wire rope configuration, overall diam, number of strands and number of wires. Is there a formual out there for this?





RE: Wire Rope Stretch/Elongation
http://www.spaceagecontrol.com/calcstre.htm
RE: Wire Rope Stretch/Elongation
RE: Wire Rope Stretch/Elongation
If this is the case then its simply back to basics:
E = (stress/strain), then just rearrange for elongation.
RE: Wire Rope Stretch/Elongation
In my industry (underground mining), rope stretch on the hoist ropes is a big deal. I think you are asking about the elastic stretch (as opposed to the constructional or permanent stretch that would be induced in the rope and is never "recovered").
Rope Stretch = P x L / (A x E)
Where P is payload or force in pounds
L is length of rope in feet
A is nominal cross sectional area (e.g. a 1 in diameter rope has an area of 0.785 sq in)
E is the modulus of the rope in psi
The E varies depending on rope construction. A few examples (from Wire Rope Industries):
Round Strand Rope
6x7 fibre core - 9 Mpsi
6x7 steel core - 10 Mpsi
6x19 fibre - 8.5 Mpsi
6x19 steel core - 9.4 Mpsi
8x19 fibre core - 5.3 Mpsi
non rotating rope, fibre core - 7.8 Mpsi
Flattened Strand Rope
6x8 fibre core - 10.5 Mpsi
6x27 fibre core - 10 Mpsi
non rotating rope - 8.5 Mpsi
Hope this helps.
Cheers,
CanuckMiner
RE: Wire Rope Stretch/Elongation
RE: Wire Rope Stretch/Elongation
Check machinery hand book also.
RE: Wire Rope Stretch/Elongation
RE: Wire Rope Stretch/Elongation
Then, before putting the wire rope to work, apply a proof load to it so that what CanuckMiner refers to as the "constructional or permanent stretch" is taken out to as great an extent as possible.
The formula might be simple and basic, 40818, but not the values you feed into that formula.