Strange Problem
Strange Problem
(OP)
Hey all- here's a weird one (at least to me.) I have a client who is looking to install a 34" i.d. 38" o.d. plate (he's suggesting 1/2" thick as a starter), supported by tensioned cables supported by the tank of a storage tank (supports would go to grade at the outer support points). They want to use this as fall arrest, but also support some equipment from it. Has anyone got any data/examples of how to tackle this problem? I am thinking that the "ring" would be a flat plate beam supported by the cables at 1/4 points of the ring circumference- but this is coming up with a thick plate, and doesn't seem right in my head. See the attached chicken scratch....
Thoughts?
Thoughts?






RE: Strange Problem
As a first shot at the horizontal pulls I would imagine four straight pieces, Then consider each bent to simulate the curve and see what moment comes up. Then you need to look at the vertical loads and bending.
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Strange Problem
RE: Strange Problem
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Strange Problem
Find some possibly illuminative equations near the bottom of this page:
http://en.wikipedia.org/wiki/Tensile_structure
Mike Halloran
Pembroke Pines, FL, USA
RE: Strange Problem
RE: Strange Problem
The essentially flat comment is related to a 2-3' sag on a 100' or so diameter tank due to restrictions. We know this will put a large load on the tank-hence my previous comment on adding reinforcing angles (or something at the connection points to the tank.)
Fall arrest was for people.
RE: Strange Problem
RE: Strange Problem
Graybeach’s approach is the best solution for the cables, since it takes the nasty issue of the ring stresses out of the problem, and saves you a bunch of cable hardware. But, you will still have much trouble making this cable arrangement work because the 100' dia. tank is just not made, nor can it be easily strengthened, to take the large concentrated reactions that the cables will induce on it. Can you strengthen the roof structure and hang this load off of it?
RE: Strange Problem
Michael.
"Science adjusts its views based on what's observed. Faith is the denial of observation so that belief can be preserved." ~ Tim Minchin
RE: Strange Problem
RE: Strange Problem
BA
RE: Strange Problem
to get an idea of the cable loads, assume they deflect 0.6deg, ie sin = 0.01.
so to carry 5,000 lbs vertically, the 4 cables will need to develop 500,000 lbs ... does that scare you ?
Quando Omni Flunkus Moritati
RE: Strange Problem