# Still Water Share Force????

Discussion in 'Hydrodynamics and Aerodynamics' started by Toru, May 16, 2015.

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### ToruNew Member

How Can I Calculate Still Water Share Force?
Is there any Standard or something for preliminary scantling calculation?
I need help.

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### gonzoSenior Member

No. You integrate the pressure from zero at the waterline to whatever is is at the bottom.

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### TANSLSenior Member

What a complicated thing !. Why not calculate the volume of water displaced, or the volume of the submerged body?
As standards for calculating scantlings, there are a lot. Each classification society has its own regulations (standards) and ISO also has them.
Perhaps you mean how to calculate the main dimensions. In that case, the standard procedure is to compare the dimensions, and the relationships among them, in similar boats.

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### NavalSArtichokeSenior Member

I'm not sure what a "share" force is.

If you are trying to size hull scantlings, TANSL's suggestion of applying the design rules of a classification society is about the quickest way to get a result. You only need the basic dimensions of the vessel to start.

If you are investigating the longitudinal strength of a vessel, then calculation of the "shear" force and the bending moment will require a certain knowledge of how the weights of the vessel are distributed longitudinally in the hull.

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### TANSLSenior Member

Yes, he is probably talking about "Still Water Shear Force", for which, it is correct, the first thing to do is calculate the weight/buoyancy distribution and bending moment values along the length of the boat. That's where, as well says Gonzo, you need to longitudinaly integrate several values and, then, calculate first derivatives of bending moment curves.

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### ToruNew Member

I am trying to use BV scanting software Mars2000. But I can not get any result without Still water share force. How can i calculate it?

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### TANSLSenior Member

You're probably not correctly using the program because, although still water SHEAR force is one of the possible calculations, it is not normal to ask for this information to continue with the calculations.
In any case, the BV has formulas to calculate SWSF based on the basic data of the project. Read the rules and you'll find many answers to your questions. In general, you can not use an scantlings software without knowing the rules.
And do not worry, it is not necessary to integrate anything. Forget that nonsense.

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### NavalSArtichokeSenior Member

It looks like you are trying to design a bulk carrier of some sort.

Like TANSL said in a previous post, when in doubt, read the rules.

For BV Rules for Classification of Steel Ships, study Part B, Chapter 5, Section 2. You may have to refer to other sections in the Rules for the definitions of certain terms.

The BV Rules can be found here at the link below:
http://www.veristar.com/portal/veri...ralinfo/giRulesRegulations/bvRules/steelships

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