Axially loaded pipes with internal pressure
Axially loaded pipes with internal pressure
(OP)
Does anyone know or has any references on how to derive the equation for an axially-loaded pipe with internal pressure. I think the critical buckling load comes
Pcr. =EI(pi)(pi)/(L)(L)
which is the same as an axially loaded pipe without internal pressure.
But how do you prove it?
Pcr. =EI(pi)(pi)/(L)(L)
which is the same as an axially loaded pipe without internal pressure.
But how do you prove it?





RE: Axially loaded pipes with internal pressure
RE: Axially loaded pipes with internal pressure
As soon as the Hencky-VonMises stress intensity exits the limit of proportionality, no gain in buckling critical stress.
RE: Axially loaded pipes with internal pressure
RE: Axially loaded pipes with internal pressure
In that world, design takes into account things such as internal pressure, slug loads, thermal loads and expansion, corrosion and such in a much more detailed way than those of us who normally work with buidlings would do. If you're dealing with one of these situations, then you really need to get your information from an experienced pipe-stress engineer, not a structural guy who dabbles in that area from time to time.
Josh
RE: Axially loaded pipes with internal pressure
RE: Axially loaded pipes with internal pressure
But, unless you're so limited by weight and have so much money that you can throw it away into space in one-shot missiles, I'd recommend not trying to "take advantage" of the small reduction in total stress that internal stress "may" bring - IF the pipe were perfectly straight and the pipe were perfectly fabricated.
Besides, I doubt that you could purchase a "pipe" with exactly the wall thickness you calculated, and will have to go to the next larger (standard wall) pipe anyway.
RE: Axially loaded pipes with internal pressure
There is a "major theme park in Central Florida" that uses pressurized pipe columns for one of its rides (a completely enclosed coaster ride, simulating a ride down a mountain)...not for the stress reduction capability, but for the crack warning that loss of pressure would show.
RE: Axially loaded pipes with internal pressure
I also remember another curious application of pipe columns with pressure, in a skyscraper in Pittsburg (the three lobed in plan) that has round columns infilled with water as a measure against fires. I always thought that very intresting, like the case where a plastic bag tank can't be pierced by a burning cigarette out of the refrigeration brought by water.
RE: Axially loaded pipes with internal pressure
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Ron, ... have not the time presently to delve in this thing now. I may look, eventually and comment. The Von Karman paper I don't find yet may be somewhere. Something of the kind of what above.
Both Galambos IV and V editions have ample sections on this and more accurate than anything I may provide, so let the interested study the texts. I myself woud have to if some critical work so asked for.
Best wishes.
RE: Axially loaded pipes with internal pressure
RE: Axially loaded pipes with internal pressure