About Aluminium 5000 Series f1 factor on DNV 2.21 Craft

[Naval_Robert]

Hi guys, i'm currently working on the design of an aluminium structure catamaran, and i'm having some trouble with finding the f1 factor for the used material following the DNV Standard for Verification 2.21 Craft.

We are planning on using two types of alloys for the aluminium plates and sheets, which are EN.AW-5182 and EN.AW-5186 both with H111 temper. The problem is that it seems like there is no specification for the f1 factor for them.

It doesn't appear in this or any other table.

If anyone knows how to proceed in this situation it would be very helpful.

Thanks!

 

[Ad Hoc]

Hi Naval_Robert,

Welcome to the forum.
The reason is that these are not commonly accepted marine grade alloys.
Thus, you need to approach DNV, to establish what values they would apply, or select a more commonly used marine grade alloy that is listed.

 

[Naval_Robert]

I see. I will probably try approaching DNV as there's little chance of changing the material at this point.

Thanks for the help !