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Re: [PSUBS-MAILIST] In my search for a simple, cheap pressure hull ...
In a message dated Tue, 6 Nov 2001 8:52:25 PM Eastern Standard Time, Ian Roxborough <irox@ix.netcom.com> writes:
>
> Hi all,
>
> I've thinking along the GRP lines for a while.
> Thought I'd pass along some information, mainly
> the material definition of GRP so any body using
> Alec Smyth's useful little spreadsheet can compare
> GRP to steel.
>
> Material definition for GRP (fiberglass matting):
>
> E = Young's Modulus : 65GPa or 9427121 psi
> Poisson's Ratio : 0.35
> Yield Stress : 1200MPa or 174039 psi
Hi,
are You sure? In my opinion the tensile strength is about 120 - 320 MPa ... can GRP realy yield...???
regards, André
> Density : 2.1 g/cm^3 or 0.06387 lbs/in3
>
> The above data is from the book "Pressure Vessels
> external pressure technology" by Carl T. F. Ross.
>
> I think testing many vessels to collapse depth is
> key before trusting your life to a GRP based pressure
> vessel.
>
> Somebody meantioned using a cardboard tube as the
> frame for constructing a GRP pressure vessel. Another
> more durable and maybe more useful method would be
> to use a section of large diameter corrugated polyethylene
> (or other plastic or GRP) piping, similar to piping
> used for drains in some areas. Done correctly, the
> corrugations will form GRP hoops giving greater strength
> to the pressure vessel (the same as steel hoops on a metal
> pressure vessel).
>
> I'm hoping to start destructively testing some
> smaller GRP pressure vessels some time next year.
> If we share our test results we should be able to
> plot some nice curves and accurately compare the
> practical results to the math side of things.
>
> I'll also post a bio at some point as well.
>
> Ian.
>
> On Wed, 7 Nov 2001 07:37:52 +1000
> "Walter Starck" <wstarck@ozemail.com.au> wrote:
>
> > Phil,
> >
> > It would seem a fairly simple thing to lay up a series of small
> > composite vessels and test to collapse depth to get some idea of
> > variability and relative strength of various resins, fibers, and
> > laminates. Do you know if this has been done and if so are the results
> > accessible?
> >
> > Walter Starck
> > Golden Dolphin Video CD Magazine
> > of diving and underwater photography
> > www.goldendolphin.com
> >
>
> --
> Stop killing everything.