Re: [PSUBS-MAILIST] Best source for structural calculations

Marc

As a mechanical engineer, the texts I found most helpful were two old naval engineering text. Actually Alec Smyth put me on to them several years back.

For the concepts and equations for designing the pressure hull, I like:

Principles of Naval Architecture - John P. Comstock (editor). Chapter 8 of the text is titled "Submarine Pressure - Hull Design" I found this very useful in designing my boat pressure hull. This text is particularly good at explaining the structural loads on the hull and failure modes with some very nice pictures of failed reinforced pressure hulls. While it does not derive the governing stress and strain equations, it does give them with quite a bit of discussion to help understand how they are applied. As this book was written in 1967, it is before the days of Finite Element Analysis (FEA). The text is quite helpful in understanding the equations used in the ABS Rules for Building and Classing --- Chapter on metallic pressure boundary components which I found to be quite terse. The analysis and discussion presented are predominately for axisymmetirc externally pressured reinforced cylindrical shells. To me the best way forward is use this text to make the initial design of the pressure hull along with the ABS spreadsheet, then go back and use an FEA tool and model the design to look for any stress anomalies. This book is out of print but you can usually find it at Amazon.com for $60-100. .

For equilibrium and stability concepts and calculations, I like:

Fundamentals of Construction and Stability of Naval Ships" by Thomas Gillmer. There are three chapters that are particularly useful . Chapter 7 - Equilibrium and initial stability, Chapter 8 - Overall Stability and Chapter 9, Dynamic Stability. Likewise, this book is out of print, but you can still find these used on Amazon.com $15-$20
.

I am sure there are newer text out there but these are the ones I used. The nice part about these text is because they are old, they are inexpensive.

Cliff

From: Marc de Piolenc <piolenc@archivale.com>
To: personal_submersibles@psubs.org
Sent: Wed, January 12, 2011 8:09:22 PM
Subject: Re: [PSUBS-MAILIST] Best source for structural calculations

Let me see if I can be a bit clearer.

Of course our field of interest draws on many fields of science, engineering and technology. I have all the basic science and engineering references, plus some semi-specialized books on naval architecture and so on. My own specialties are aeronautical engineering (lighter than air) and aero-propulsion, especially ducted propulsors. I also have a long-standing interest in shell structures and in ferrocement shells for both housing and boats.

What I'm looking for is a text that treats submarine structures SPECIFICALLY, starting with the basic system of forces acting on the pressure hull (which in most manned subs will be the major structural member) and progressing from there, first to the exact mathematical relations used in stress analysis OF THIS PARTICULAR TYPE OF STRUCTURE SUBJECTED TO THIS SYSTEM OF FORCES, and from there to the approximate formulas needed for preliminary design.

I have what I THINK is a valid picture of the forces on the pressure hull, and I've been accumulating literature on axisymmetric structures under combined - external pressure and axial compresion - loading, but there's longitudinal bending to be taken care of, too, and I want to make sure I'm on the right track, because I'm basically self-taught in structures.

Thanks in advance.

Best,
Marc

On 1/13/2011 8:16 AM, Sean T. Stevenson wrote:
> Marc - I'm not entirely sure what you're looking for here. From your
> description, I'm tempted to suggest going back to the basic physics - strength
> of materials, mechanics, thermodynamics and so forth, but I'm guessing that
> this is not what you mean. Are you looking for a single reference that covers
> mechanical engineering topics? References like the Machinery's Handbook have
> most of the relevant formulas - post-derivation. If you want to understand
> structural calculations all the way from first principles, then you need a
> background in engineering or mathematics, because there is a fair bit of
> calculus involved. Or do I completely misunderstand your intent?
>
> -Sean
>

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