ISO 12215-5 Help

Dear All. I'm wondering if someone can help me.

I'm working through ISO 12215-5 to demonstrate to my students how you determine the Dimensions of panels and stiffeners. It explains the definition of what they are but doesn't explain how you actuially calculate the dimensions. Maybe i'm missing something.
I've got the spreadsheet with the standard however i'd like to know how the dimensions are calculated.

Any help anyone could give me would be fantastic.

Many thanks

 

You mean this:

 

Many thanks for your responses.
I understand the symbols, b, l, lu and s but I still don't understand how you calculate their values. The standard sets out clearly what the symbols are with pictures but i'd like to know how you actual work out the spacings on a vessel.

Sorry for being a nuisance.

Thanks again

 

Then i fear your ability to teach this subject is beyond you.

One does not calculate it.
As the designer YOU decide what the frame spacing is and the stiffener spacing is...why?..because it influences so much of the structure, the weight, the production costs etc.

 

You may elect to use arbitrary values for l and s but if you read further down the rules, there is a maximum value for l as defined by the formula. And if you read further still, there is a ratio for l/b (panel aspect ratio) for which there is a corresponding aspect ratio correction factor that you have to apply within the constraint of the rules.

You have to understand the rules completely and know it by heart before you can teach.

 

Ad Hoc. Thank you for the second part of your response, that makes sense. As to the first part and my ability to teach. I teach Marine Engineering not Naval Architecture, one of my students asked and I took the time to come on here to speak to an expert. I would have taken offense to your comment until I saw your other posts on other questions. Says it all.

 

Thanks RX much more helpful.

 

It is not your ability to teach that is in question - I don't know you from a bar of soap
But it is in reference to your ability to teach/advice THIS subject, if you do not understand the core definitions to begin with.
That's all.

 

Ad Hoc. Thank You. Going on my research into this as I am keen to learn. Also when my students ask questions I like to go away and find the answer. Has there been any study into recommended frame spacing longitudinally and transversely per different materials and size of material. Or possible rule of thumbs. Its interesting that I'm not the only one to be asking this question, it seems to cause confusion to others on here. Many thanks

 

Simple answer - yes!

But is is just a simple matter of aspect ratio, i.e panel size.

If you can get your students to put ISO into a simple spreadsheet...get the to assume certain particulars of a vessel, then alter the frame spacing and stiffener spacing...see what modulus is required, and plate thickness, and then calculate the weight for each variation. This is most instructive for students. I have done such in a book i've just written, see below: