Keels and Keels Again!

[MikeJohns]

But you presuppose that the naval architect hasn't actually specified the size and shape of the backing plate !

I'd also be very careful of your definitions here since I can't think of any other term that would describe a shaped inner metal plate that is structurally designed specifically for example to increase the shear area.

I'm also very curious as to how anyone could presume to do an FEA analysis or engineering load study without considering the mounted keel and that includes the laminate. I posted before that it's tricky and that it's reasonable to look at modeling it with an isotropic material while matching the E values for the laminate then at least you get the non linear structural response under load.

[philSweet]

But you presuppose that the naval architect hasn't actually specified the size and shape of the backing plate !

Yes, I did presume that, and I said as much in a different way.

I'd also be very careful of your definitions here since I can't think of any other term that would describe a shaped inner metal plate that is structurally designed specifically for example to increase the shear area.

Ok, I don't want to cause a semantics argument, I was looking at tracing the load towards the keel from the plate. If there isn't another name for the thing in question, there isn't. Then again it doesn't seem to be a common practice to span wide with an interior plate. If it were commonly done it might get its own name.

Not sure if this applies to me, I didn't mention FEA either. For a design of modest ambitions, you might verify a proposed design with FEA but I doubt you design with FEA in hand all along the way. And where would you bound the problem? You'd need to model half the ship to get it right.

[MikeJohns]

Originally Posted by philSweet

........you might verify a proposed design with FEA but I doubt you design with FEA in hand all along the way. And where would you bound the problem? You'd need to model half the ship to get it right.

Phil
Sorry, I missed that post.
Usually several studies are required, large scale to look at the load path from the chainplates through to the keel attachment.
Then localised studies to check an adequate FOS for the moment transfer from the keel to the hull.