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-   -   Upper limit to size of Air Supported Structure?? (http://www.physicsforums.com/showthread.php?t=672997)

Stupid Genius Feb19-13 05:40 PM

Upper limit to size of Air Supported Structure??
 
Hey yall! Im new here, and I'd like to ask a question I can't seem to get an answer to anywhere else, so why not get it here! I'll get right to it! The question is...What is the upper limit of an air supported structure, and what is the maximum safe pressure inside said structure? Can they simply be made as large as you would like? Or is there limits such as outside wind force, inside pressure of structure relative to overall weight of the structure, the structure tearing from the immense forces created by rising air, shape of structure, volume of air within structure ect. please list the equations or whatever else involved in your reasoning, thanks!

jedishrfu Feb19-13 05:47 PM

Re: Upper limit to size of Air Supported Structure??
 
Why are you interested in this?

Is this for a school project?

I've seen some pretty big jumping playhouses for kids supported by fans.

Are you thinking bigger?

http://en.wikipedia.org/wiki/Air-supported_structure

http://www.bigspanstructures.com/ind...FQLznAodQBUAMg

Stupid Genius Feb19-13 06:21 PM

Re: Upper limit to size of Air Supported Structure??
 
No this isn't for school, and I'm thinking big, like the biggest it can get. Not specifically blow up structures like playhouses, but more so like the inflated white golf domes you see from place to place, how big can they theoretically be?

jedishrfu Feb19-13 07:14 PM

Re: Upper limit to size of Air Supported Structure??
 
Quote:

Quote by Stupid Genius (Post 4277311)
No this isn't for school, and I'm thinking big, like the biggest it can get. Not specifically blow up structures like playhouses, but more so like the inflated white golf domes you see from place to place, how big can they theoretically be?


i think the link to wikipedia gives you an idea of how far engineers and architects have dared. I'm sure there's a tolerance factored for extreme weather and material stress limits as well as fan power consumption. However you're not going find the design equations here beyond the simple physics of roof weight to air pressure.

CWatters Feb20-13 07:59 AM

Re: Upper limit to size of Air Supported Structure??
 
I suppose if people want to use it the bends would limit the maximium pressure difference :-)

etudiant Feb20-13 02:40 PM

Re: Upper limit to size of Air Supported Structure??
 
Air supported structures can be enormous, because the bigger the structure, the less the pressure differential needed to keep them inflated. So they are very user friendly, apart from the need to go through limited entrances.
The problems arise at the coupling points, where the structure meets its mooring, because the stresses have to be distributed from there.
The other challenge is precipitation, which can impose very large localized loads that an air supported structure has difficulty dealing with. There is a video on line of such a failure in an air supported arena roof, Denver or Minneapolis, I think, which illustrates that very well.


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