section modulus

[lyqqmxm]

hi all

a simple question , when calculate section modulus of stiffener , if the outer

skin of effective plating for sandwich should also be calculated .

thanks

[MikeJohns]

Depends on the rules you are working to.
Some allow the full width between stiffeners as the outer flange , Good general practice is to use around 15 times the skin thickness for the flange if you are submitting specific design.

[lyqqmxm]

Depends on the rules you are working to.



i used ISO12215-5, if the outer skin of effective plating for sandwich should also be calculated .

[terhohalme]

Look at 12215-5, article 11.5, table 19, note a).

[lyqqmxm]

Look at 12215-5, article 11.5, table 19, note a).

Thank above , but i never know 12215-5 contain article 11, my edition is 12215-5.3(2004-12-18)

can you tell me how to fine article 11 , thank you every much

[terhohalme]

Mine is ISO/FDIS 12215-5:2006(E) 2006-01-03. It is not harmonised standard yet, so it can be diffucult to get. I have it for testing and decleration and can't send a copy.

[lyqqmxm]

Mine is ISO/FDIS 12215-5:2006(E) 2006-01-03. It is not harmonised standard yet, so it can be diffucult to get. I have it for testing and decleration and can't send a copy.


Thank you for your answer, i only want to know if the outer skin of effective plating for sandwich should also be calculated when calculate section modulus of stiffener. :(

Someone tell me calculate normally include the inner laminate only in the effective plate. This is because the foam core have a very low capacity in distributing the force from the inner laminate to the outer laminate of the sandwich construction.

But i think the sandwich laminate is a integrated system and effective plating extent definition is 20(ti+to), so even if "core with low capacity in distributing the force ", the outer skin play the role in structure.

which is right?:confused: if you kown, please tell me answer , thank you for you

[terhohalme]

Yes, you are right, calculate both 20(ti+to). This is also how I realize it.

[lyqqmxm]

Yes, you are right, calculate both 20(ti+to). This is also how I realize it.

Thank you :) , i'm a novice. This a good beginning and if you don't mind,

please give me an answer that

http://www.boatdesign.net/forums/showthread.php?t=21125