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Re: [PSUBS-MAILIST] Pressure Hulls
Hi Ian,
Interesting formula. Let me see if I understand it with an example, below.
----- Original Message -----
From: "Ian Roxborough" <irox@ix.netcom.com>
To: <personal_submersibles@psubs.org>
Sent: Sunday, June 30, 2002 7:53 PM
Subject: Re: [PSUBS-MAILIST] Pressure Hulls
> P = 2Ut/R
> Where:
> U = min yield strength
> t = hull thinkness
> R = outside radius
Let's say we're talking about something a little tougher than mild steel;
say 0.4% carbon steel ("boiler plate") with a Tensile Strength of 44,000
psi, and a Yield Point of 30,000 psi. Then:
U = 30,000 psi.
If we have a 9-foot O.D. sphere of one inch thick boiler plate, then:
T = 1"
R = 54"
Then:
P = 1,111.11 psi
And if D = P multiplied by 2.245, then:
D = 2494.444 FSW
Und Zo...she pops at about 2,500 feet. Operating depth could be, maybe,
1,250 FSW ; 830 feet would be even safer.
I'm asking myself now if I think a 9-foot sphere made out of one-inch boiler
plate could go that deep before imploding. Hmmm....it might.
Is this how you figure the formula works, Ian?
BTW: Dewey, I am NOT saying your sphere is suitable for this depth; I don't
know anything about that particular vessel, and there could be a lot of
things about it that might throw the numbers right out the door: exact type
of metal, imperfections in shape or welding, dents, corrosion, modifications
like windows and hatches, etc.. This is just an experiment with the
formula, using assumed variables and metal properties.
Anybody else wanna take a crack at this? Comments?
Pat