Point Loads on Water Tank Shells
Point Loads on Water Tank Shells
(OP)
I am designing an antenna array support frame to be mounted on top of a water tank (on the shell's crown). Rather than a finite element modelling of the entire tank shell, does anyone have any references for hand calculations and approaches for analyzing the tank shell for local loads introduced by the antenna support frame?
The entire antenna support frame will be subject to overturning due to wind loads, so at each of the connections of support posts to the shell there will be either an uplift or downward load. Therefore, the load on the shell will not just be a uniform pressure or suction.
Thanks for the help.
The entire antenna support frame will be subject to overturning due to wind loads, so at each of the connections of support posts to the shell there will be either an uplift or downward load. Therefore, the load on the shell will not just be a uniform pressure or suction.
Thanks for the help.






RE: Point Loads on Water Tank Shells
RE: Point Loads on Water Tank Shells
RE: Point Loads on Water Tank Shells
RE: Point Loads on Water Tank Shells
The "pressure Vessel Design Handbook" by Henry Bednar
has a section on local stresses in shells due to attachments.
For your case;
radius (r) = 144 in
t = 1/4" - c.a.
corrosion allowance = 1/16"
force (F) = 5000 lbs
L = perimiter of attachment pad (foot print)
assume L = 72" ( 18" square pad)
Stress = [1.75*(F/L)*sqrt(r*t)]/t^2
= 17,962 psi
Also check out ;
Welding Research Council (WRC) bulletin 107
hope this helps
Warren
RE: Point Loads on Water Tank Shells
I have been down this road before. The telecom industry is pushing hard. I think what you are attempting is not safe. Your point loads are too high. In all probablity the original design may not have treated the tank as a shell. The old guys designed these as membranes, large steel bladders. The only way I would attempt this is by keeping my reactions to less than 300 lbs.
Regards
VOD