[PSUBS-MAILIST] ABS Hull Calc

[Pete Niedermayr via Personal_Submersibles]

Thanks Jon. What is n ? Is that the safety margin ?
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On Wed, 4/23/14, Jon Wallace via Personal_Submersibles <personal_submersibles at psubs.org> wrote:

 Subject: Re: [PSUBS-MAILIST] ABS Hull Calc
 To: "Personal Submersibles General Discussion" <personal_submersibles at psubs.org>
 Date: Wednesday, April 23, 2014, 5:34 PM
 
 
 You have to put in some kind of value and as I recall, very
 small numbers can come up with some weird results.  If
 you use 36" OD, 72" length, and .25" thickness for the
 shell, and then enter .1" for the stiffeners, you'll see
 that the bottom line calculation (line 92) is a max depth of
 1 foot.  However, if you look at line 51 which is the
 maximum Pa for inter-stiffener strength you'll note that it
 is 61.2 psi which matches the results of the unstiffened
 online calculator.  Note that both of these results
 correspond to a "n" of .8 which you can manipulate in the
 excel spreadsheet but is hard-wired in the unstiffened
 calculator.
 
 So I think the answer is that you have to use very small
 number for lines 18 through 21 (try .001) but ignore line 92
 and find the lowest Pa between lines 51, 56, 63, and 71 to
 determine the maximum allowable operating pressure.
 
 Jon
 
 
 
 
 On 4/23/2014 7:02 PM, Pete Niedermayr via
 Personal_Submersibles wrote:
 > What do I enter if I don't want to have hull stiffners.
 I want to compare results with the Psubs online calculator
 > 
 > Thanks Pete
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 > Personal_Submersibles at psubs.org
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