[PSUBS-MAILIST] External Shapes

[Joe Perkel]

Sean,

Because I really don't know how to do it. As internal stiffener designs go. I have a ready template in the K-350.

I would like to go outside with a double hull design if I could do it right and answer ongoing maintenance. 

Some interesting reduced scale replica options present themselves this way.

Joe

Sent from my iPhone

On Apr 4, 2014, at 5:29 PM, "Sean T. Stevenson" <cast55 at telus.net> wrote:

> That said, if you are building outside the hull envelope anyway, why not design an optimized hull with external framing? It requires full penetration 100% NDT welding, but is otherwise stronger than an internally stiffened design.
> 
> Sean
> 
> 
> On April 4, 2014 3:25:16 PM MDT, "Sean T. Stevenson" <cast55 at telus.net> wrote:
>> 
>> You are likely to run into a problem with total weight, and hence carrying capacity. The reason we use stiffeners at all is to create a more efficient structure, where the various modes of failure all have similar probabilities. Unstiffened cylinders save the additional work and welding of a multi-part structure, but have to be comparatively thicker to withstand the buckling modes, meaning you have a structure which has more strength than is necessary for some modes of failure, and consequently is heavier. While you are correct that you can add additional superstructure to the outside of the unstiffened cylinder without reducing its strength, you might end up having to use the superstructure to attach syntactic foam blocks to offset the necessarily heavy hull.
>> 
>> Sean
>> 
>> 
>> On April 4, 2014 12:58:28 PM MDT, Joe Perkel <josephperkel at yahoo.com> wrote:
>>> 
>>> Please confirm or rebuke the following train of thought.
>>> 
>>> If one were to use an unsupported cylinder of sufficient sizing for the intended design depth,...then that same design is free to use external framing to form an external shape of choice? 
>>> 
>>> Assume uneven spacing of said frames.
>>> 
>>> Joe
>>> 
>>> Sent from my iPhone
>>> 
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> 
> -- 
> Sent from Kaiten Mail. Please excuse my brevity.
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