Guy Wire Tension and Shear
Guy Wire Tension and Shear
(OP)
I'm having a discussion with other people at my company on how much load a continuous wire rope can hold.
Example:
A continuous wire rope is threaded thru a pulley attached to a pole. They are attached at the ground at the same point. For a load of, say 4000#, each leg takes 2000#. The rated breaking strength of the wire rope is 4000#.
Question: Since each leg is taking one-half of the load, can the 4000# load be increased to 8000#. Is the tension at the point of contact with the top of the pulley 4000# or 8000#, thereby exceeding the rated breaking stength.
Also, will the shear at this point be 4000# or 8000#.
Thank you for your help.
Example:
A continuous wire rope is threaded thru a pulley attached to a pole. They are attached at the ground at the same point. For a load of, say 4000#, each leg takes 2000#. The rated breaking strength of the wire rope is 4000#.
Question: Since each leg is taking one-half of the load, can the 4000# load be increased to 8000#. Is the tension at the point of contact with the top of the pulley 4000# or 8000#, thereby exceeding the rated breaking stength.
Also, will the shear at this point be 4000# or 8000#.
Thank you for your help.






RE: Guy Wire Tension and Shear
i think the tension in ths cable is 4000# throughout the length of the cable. At the top, by the pulley block, one 4,000 lbs is reacting the other, rather than doubling the load in the cable. same for the shear load.
RE: Guy Wire Tension and Shear
The shear in the "pole" (again, this is a poor choice of word--if it is a horizontal member, it is a beam) will depend on where the supports for the "pole" occur, relative to the location of the pulley.
DaveAtkins
RE: Guy Wire Tension and Shear
RE: Guy Wire Tension and Shear
but caution, some failures are not linear with applied load.
i'd prefer to apply the load required, and calculate MSs accordingly ... seems more direct and takes no longer to do.
RE: Guy Wire Tension and Shear
RE: Guy Wire Tension and Shear
Thank you DCR1. You are consistent with myment, however, I need something in writing to prove it to the others. Do have something. I've checked statics books, mechanics of materials and other civil books. Nothing has any thing that shows what we are saying for the point of the connection. Any help will be appriciated.
RE: Guy Wire Tension and Shear
www.SlideRuleEra.net
RE: Guy Wire Tension and Shear
Thank you SlideRuleEra for the information. One more question. With the guy going through the pulley and then both parts anchored to the ground, would you call this a one or two part line?
RE: Guy Wire Tension and Shear
then I would certainly consider that situation a two-part line.
An analogy is to look at an upside-down similar situation. At steady state (no movement of the line) the load on this platform is equal to the weight supported by the pulley (not counting the weight of the "stick-person"
www.SlideRuleEra.net
RE: Guy Wire Tension and Shear
Thank you.