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need to know if these compounds can be used for a hull

need to know if these compounds can be used for a hull

(OP)
can you use a treated carbon fiber for a hull of a submarine it seems feasible and lifht weight im just unsure about its integrity to withstand pressure   plus it would be extremly light weight


_____________________________________________________________
the real heros are the ones unnamed and unknown and that only exist in the shadows

RE: need to know if these compounds can be used for a hull

Carbon fiber by itself is very strong, but a hull woven from fibers alone would be flexible, even limp.  A carbon fiber composite also includes a matrix, like epoxy resin, which is responsible for making the composite stiff.  Composites may or may not make good submarine hulls, depending on how deep you want to go, and whether the interior is flooded or not.

Light weight would be a virtue in a flooded sub, like divers use, where it would allow budgeting weight and strength for other things.

Light weight is not a virtue in a non- flooded sub, where you typically have to add ballast to offset the natural buoyancy of the hull.

Mike Halloran
Pembroke Pines, FL, USA

RE: need to know if these compounds can be used for a hull

(OP)
what if the carbon fiber was heat treated graphitized do you beleive that should be able to work in any situation and the depths that i will be going will not be that deep only about 75 -100 ft at most

RE: need to know if these compounds can be used for a hull

Carbon fiber is just that, a fiber.  It's already very strong in tension.  Like any fiber, it has little strength in compression, because the fibers are long and thin.

I'm not aware that you could improve it by heat treating it, since it's already been heated.  Some, at least, is made by roasting rayon fiber.

Graphite is a form of carbon.  You could coat the carbon fiber with graphite, I guess.  That would make it slippery, which in a composite, is A Very Bad Thing.

You need to do some reading.  First, you need to understand the difference between 'carbon fiber' and 'carbon fiber composite'.  You are clearly confusing the two.

I know carbon fiber composite is all the rage these days in real race cars, where it has some virtues that offset its cost.  But it's not magic.  It's really just a bit stiffer and stronger than glass fiber composite, so it can be made a bit thinner and therefore lighter.

I'm suspicious that a lot of faux carbon fiber composite is also being sold for faux race cars, but that's another discussion.

Now, as for making a submarine hull out of carbon fiber _composite_, yes, it's possible.  It may not be the best material for the job.  It's certainly not the cheapest.

Before you get too much farther, you need to get a price for a couple miles of carbon fiber tape.



Mike Halloran
Pembroke Pines, FL, USA

RE: need to know if these compounds can be used for a hull

Spend some time looking through ASME III (Unfired Pressure Vessels) for vessels under external pressure.  And keep in mind that if you intend to operate at 100 ft (~45 psi) that you'll want a hefty margin against any kind of pressure boundary buckling failure.  Think in terms of emergency recovery time from a depth overshoot if you experience horizontal control plane malfunction while descending at some speed and down angle when nearly at your maximum operating depth.

I may be able to find a more specific ASME reference for you, but for a number of reasons I don't think I can provide any hints as regards a design collapse depth, so you're on your own there.


Norm

RE: need to know if these compounds can be used for a hull

also look under ASME PVHO (Human occupancy)  & Sec. X {fiber reinforced plastic) pressure vessel codes

RE: need to know if these compounds can be used for a hull

(OP)
hey sorry for the delay computer was down
you know were i can get a copy of the asme codes free like an ebook or pdf that would be mutch appreciated if you could

thanks for the help

RE: need to know if these compounds can be used for a hull

Try your local engineering college library

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