Steel cable supporting Wind Load
Steel cable supporting Wind Load
(OP)
I have a steel cable supporting a net. The entire system is about 60' high, but the application will have a steel cable supporting 50' vertical of netting. I have to treat the net as if it is seeing all of the wind load, which comes out to be about 23psf after all factors. The span is going to be 20'-30'.
How do I go about transferring the 1150plf line load on the cable into the tension on the supports. I am familiar with the catenary equations, which relate the horizontal load, weight per foot, and sag, but how do I eliminate one of the variables? How do I know how much sag will occur and therefore will be able to calculate the horizontal force?
I assume that there is a way to relate the amount of sag to the properties of the steel cable, but any help is appreciated.
Thanks
How do I go about transferring the 1150plf line load on the cable into the tension on the supports. I am familiar with the catenary equations, which relate the horizontal load, weight per foot, and sag, but how do I eliminate one of the variables? How do I know how much sag will occur and therefore will be able to calculate the horizontal force?
I assume that there is a way to relate the amount of sag to the properties of the steel cable, but any help is appreciated.
Thanks






RE: Steel cable supporting Wind Load
1. I suppose you could go through all the calcs and figure how much it lenghthens - but why bother.
2. Put the cable up and pull at the center with all your might - there is your sag??
3. Archoneng.com has neat little software for about $40 that does a great job.
RE: Steel cable supporting Wind Load
If the offset is h, the tension in the cable is wL^2/8h.
BA
RE: Steel cable supporting Wind Load
Is it common to call out a specific sag under load?
Also, good catch on being a porabola under horizontal load.
RE: Steel cable supporting Wind Load
Structural Engineering Handbook
Section 27, Lew, Scarangello
Suspension Roofs
Design of Suspension Systems
4. Single Cable under Uniform Distributed Load
Gaylord, Gaylord, Stallmeyer
4th Ed. (that I have)
McGraw-Hill NY 1997
Respect the question and using the equations there given, one may assume a guess answer for the standing sagitta (hence an elongated longer length of the cable than the span), and then iteratively test for compliance of the set of equations for the assumed section. I think this can be done with Mathcad set to find the sagitta (varying it) that meets all the conditions, but have not done. May do it, next weeks.
Also pay attention to the dynamic effects etc named in the text.
RE: Steel cable supporting Wind Load
The amount of elongation is variable depending on the type of cable used and whether or not it has been pre-stretched.
BA
RE: Steel cable supporting Wind Load
y = L(3wL/64EA)^.3333
for a cable with zero initial tension.
RE: Steel cable supporting Wind Load
RE: Steel cable supporting Wind Load